Publications

Maximilian Obst, Tobias Nörenberg, Gonzalo Álvarez-Pérez, Thales V. A. G. de Oliveira, Javier Taboada Gutierrez, Flávio H. Feres, Felix G. Kaps, Osama Hatem, Andrei Luferau, Alexey Y. Nikitin, J. Michael Klopf, Pablo Alonso-González, Susanne C. Kehr and Lukas M. Eng

ACS nano 17 19, 19313-19322 (2023)

D. Santos-Cottin, I. Mohelský, J. Wyzula, F. Le Mardelé, Itzik Kapon, S. Nasrallah, N. Barišić, I. Živković, J. r. Soh, F. Guo, K. Rigaux, M. Puppin, J. h. Dil, B. Gudac, Z. Rukelj, M. Novak, Alexey Kuzmenko, C. c. Homes, Tomasz Dietl, M. Orlita and Ana Akrap

Physical review letters 131 18, 186704 (2023)

Yixi Zhou, Adrien Waelchli, Margherita Boselli, Iris Crassee, Adrien Bercher, Weiwei Luo, Jiahua Duan, J.l.m. van Mechelen, Dirk Van Der Marel, Jérémie Teyssier, Willem Rischau, Lukas Alexander Korosec, Stefano Gariglio, Jean-Marc Triscone and Alexey Kuzmenko

Nature communications 14 1, 7686 (2023)

Phonon polaritons are promising for infrared applications due to a strong light-matter coupling and subwavelength energy confinement they offer. Yet, the spectral narrowness of the phonon bands and difficulty to tune the phonon polariton properties hinder further progress in this field. SrTiO…

Teodor Luibrand, Adrien Bercher, Rodolfo Rocco, Farnaz Tahouni-Bonab, Lucia Varbaro, Willem Rischau, Claribel Dominguez Ordonez, Yixi Zhou, Weiwei Luo, Soumen Bag, Lorenzo Fratino, Reinhold Kleiner, Stefano Gariglio, Dieter Koelle, Jean-Marc Triscone, Marcelo J. Rozenberg, Alexey B. Kuzmenko, Stefan Guénon and Javier Del Valle Granda

Physical review research 5, 013108 (2023)

Mattias Matthiesen, Jorrit R. Hortensius, Samuel Mañas-Valero, Itzik Kapon, Dumitru Dumcenco, Enrico Giannini, Makars Šiškins, Boris A. Ivanov, Herre S. J. van der Zant, Eugenio Coronado, Alexey Kuzmenko, Dmytro Afanasiev and Andrea Caviglia

Physical review letters 130 7, 076702 (2023)

Michael Dapolito, Makoto Tsuneto, Wenjun Zheng, Lukas Wehmeier, Suheng Xu, Xinzhong Chen, Jiacheng Sun, Zengyi Du, Yinming Shao, Ran Jing, Shuai Zhang, Adrien Bercher, Yinan Dong, Dorri Halbertal, Vibhu Ravindran, Zijian Zhou, Mila Petrovic, Adrian Gozar, G. L. Carr, Qiang Li, Alexey Kuzmenko, Michael M. Fogler, D. N. Basov, Xu Du and Mengkun Liu

Nature nanotechnology (2023)

Margherita Boselli, Gernot Scheerer, Michele Filippone, Weiwei Luo, Adrien Waelchli, Alexey Kuzmenko, Stefano Gariglio, Thierry Giamarchi and Jean-Marc Triscone

Physical review. B. 103, 075431 (2021)

Nanoscale channels realized at the conducting interface between LaAlO3 and SrTiO3 provide a perfect playground to explore the effect of dimensionality on the electronic properties of complex oxides. Here we compare the electric transport properties of devices realized using the atomic force…

T. M. Slipchenko, Jean-Marie Poumirol, Alexey Kuzmenko, A. Yu. Nikitin and L. Martín-Moreno

Communications physics 4 1, 110 (2021)

Studying the collective excitations in charge neutral graphene (CNG) has recently attracted a great interest because of unusual mechanisms of the charge carrier dynamics. The latter can play a crucial role for formation of recently observed in twisted bilayer CNG graphene plasmon polaritons (GPPs)…

Ivan Ardizzone, Jérémie Teyssier, Iris Crassee, Alexey Kuzmenko, D. G. Mazzone, D. J. Gawryluk, M. Medarde and Dirk Van Der Marel

Physical Review Research 3 033007 (2021)

The rare earth nickelates RNiO3 are metallic at high temperatures and insulating and magnetically ordered at low temperatures. The low temperature phase has been predicted to be type II multiferroic, i.e., ferroelectricand magnetic order are coupled and occur simultaneously. Confirmation of those…

Bastien Michon, Alexey Kuzmenko, Michaël Tran, Benjamin Robert Mc Elfresh, S. Komiya, S. Ono, S. Uchida and Dirk Van Der Marel

Physical review research 3 4, 043125 (2021)

One of the most widely discussed features of the cuprate high-Tc superconductors is the presence of a pseudogap in the normal state. Recent transport and specific heat measurements have revealed an abrupt transition at the pseudogap critical point, denoted p∗, characterized by a drop in carrier…

Weiwei Luo, Alexey Kuzmenko, Jialin Qi, Ni Zhang, Wei Wu, Mengxin Ren, Xinzheng Zhang, Wei Cai and Jingjun Xu

Nano letters 21 12, 5151-5157 (2021)

Dual-gate tuning on two-dimensional (2D) heterostructures can provide independent control of the carrier concentration and interlayer electrostatic potential, yielding novel electronic and optical properties. In this paper, by utilizing monolayer graphene as both the top gate and a plasmon…

Jean-Marie Poumirol, Adrien Bercher, Tetiana Slipchenko, Ivan Maggio-Aprile, Christoph Renner and Alexey Kuzmenko

Physical review applied 16 4, 044012 (2021)

We present a very-compact bicomponent-permanent-magnet design capable of generating 1.25 T in a small volume, significantly above the 0.6 T available from a single uniformly magnetized permanent magnet. In addition to the enhanced maximum field, our design drastically limits the stray field present …

Ivan Ardizzone, M. Zingl, Jérémie Teyssier, H. U. R. Strand, Oleg Peil, Jennifer Fowlie, A. B. Georgescu, Sara Catalano, Nimrod Bachar, Alexey Kuzmenko, Marta Gibert Gutierrez, Jean-Marc Triscone, Antoine Georges and Dirk Van Der Marel

Physical Review. B, Condensed Matter 102 15, 155148 (2020)

Materials with strong electronic correlations host remarkable — and technologically relevant — phenomena such as magnetism, superconductivity and metal-insulator transitions. Harnessing and controlling these effects is a major challenge, on which key advances are being made through lattice and…

Weiwei Luo, Margherita Boselli, Jean-Marie Poumirol, Ivan Ardizzone, Jérémie Teyssier, Dirk Van Der Marel, Stefano Gariglio, Jean-Marc Triscone and Alexey Kuzmenko

Nature Communications 10 2774 (2019)

Probing the local transport properties of two-dimensional electron systems (2DES) confined at buried interfaces requires a non-invasive technique with a high spatial resolution operating in a broad temperature range. In this paper, we investigate the scattering-type scanning near field optical…

Ievgeniia O. Nedoliuk, Sheng Hu, Andre K. Geim and Alexey Kuzmenko

Nature Nanotechnology 14 8, 756-761 (2019)

When two-dimensional electron gases (2DEGs) are exposed to a magnetic field, they resonantly absorb electromagnetic radiation via electronic transitions between Landau levels1. In 2DEGs with a Dirac spectrum, such as graphene, theory predicts an exceptionally high infrared magneto-absorption, even…

S. Borroni, Jérémie Teyssier, P. Piekarz, Alexey Kuzmenko, A. M. Oleś, J. Lorenzana and F. Carbone

Physical Review. B, Condensed Matter 98 18 (2018)

We present inelastic light scattering data on a single crystal of magnetite (Fe3O4) across the Verwey transition. We identify anomalies of the lattice vibrations that originate from strong coupling to electronic excitations. We reveal spectroscopic signatures of diffusive modes in the electronic…

Michele Tamagnone, Tetiana M. Slipchenko, Clara Moldovan, Peter Q. Liu, Alba Centeno, Hamed Hasani, Amaia Zurutuza, Adrian M. Ionescu, Luis Martin-Moreno, Jérôme Faist, Juan R. Mosig, Alexey Kuzmenko and Jean-Marie Poumirol

Physical review 97 24, 241410 (2018)

Faraday rotation is a fundamental property present in all nonreciprocal optical elements. In the THz range, graphene displays strong Faraday rotation; unfortunately, it is limited to frequencies below the cyclotron resonance. Here, we show experimentally that in specifically designed metasurfaces,…

Liang Yang, Jing Tian, Henry Giddens, Jean-Marie Poumirol, JingBo Wu, Alexey Kuzmenko and Yang Hao

Applied physics letters 112 15, 151103 (2018)

At the terahertz spectrum, the 2D material graphene has diagonal and Hall conductivities in the presence of a magnetic field. These peculiar properties provide graphene-based structures with a magnetically tunable response to electromagnetic waves. In this work, the absolute reflection intensity…

Ievgeniia Nedoliuk

Thèse (2018)

The goal of this work is measuring magneto-optical spectra of high quality graphene crystals in the terahertz and infrared regions in order to understand magneto-optical phenomena in graphene unperturbed by defects, impurities, inhomogeneities of chemical potential, etc. For this purpose we used…

Nicolas Ubrig, Sanghyun Jo, Marc Philippi, Davide Costanzo, Helmuth Berger, Alexey Kuzmenko and Alberto Morpurgo

Nano letters 17 9, 5719-5725 (2017)

The band structure of many semiconducting monolayer transition metal dichalcogenides (TMDs) possesses two degenerate valleys, with equal and opposite Berry curvature. It has been predicted that, when illuminated with circularly polarized light, interband transitions generate an unbalanced…

E. Baldini, A. Mann, L. Benfatto, E. Cappelluti, A. Acocella, V. M. Silkin, S. V. Eremeev, Alexey Kuzmenko, S. Borroni, T. Tan, X. X. Xi, F. Zerbetto, R. Merlin and F. Carbone

Physical review letters 119 9, 097002 (2017)

In systems having an anisotropic electronic structure, such as the layered materials graphite, graphene, and cuprates, impulsive light excitation can coherently stimulate specific bosonic modes, with exotic consequences for the emergent electronic properties. Here we show that the population of E2g …

Manisha Chhikara, Iaroslav Gaponenko, Patrycja Paruch and Alexey Kuzmenko

2D materials 4 2, 025081 (2017)

Graphene is a mechanically robust 2D material promising for flexible optoelectronic applications. However, its electromagnetic properties under strain are experimentally poorly understood. Here we present the far-infrared transmission spectra of large-area chemical-vapor deposited monolayer…

Jean-Marie Poumirol, Peter Q. Liu, Tetiana M. Slipchenko, Alexey Y. Nikitin, Luis Martin-Moreno, Jérôme Faist and Alexey Kuzmenko

Nature communications 8 1, 14626 (2017)

The magnetic circular dichroism and the Faraday rotation are the fundamental phenomena of great practical importance arising from the breaking of the time reversal symmetry by a magnetic field. In most materials, the strength and the sign of these effects can be only controlled by the field value…

Pieter Jan De Visser, Julien Levallois, Michaël Tran, Jean-Marie Poumirol, Ievgeniia Nedoliuk, Jérémie Teyssier, Ctirad Uher, Dirk Van Der Marel and Alexey Kuzmenko

Physical Review Letters 117 1, 017402 (2016)

We measure the far-infrared reflectivity and Kerr angle spectra on a high-quality crystal of pure semimetallic bismuth as a function of magnetic field, from which we extract the conductivity for left- and right-handed circular polarizations. The high spectral resolution allows us to separate the…

S. A. Klimin, Alexey Kuzmenko, M. A. Kashchenko and M. N. Popova

Physical review 93 5, 054304 (2016)

We present a comparative far-infrared reflection spectroscopy study of phonons, phase transitions, spin-phonon, and electron-phonon interactions in isostructural multiferroic iron borates of gadolinium and terbium. The behavior of phonon modes registered in a wide temperature range is consistent…

Michele Tamagnone, Clara Moldovan, Jean-Marie Poumirol, Alexey Kuzmenko, Adrian M. Ionescu, Juan R. Mosig and Julien Perruisseau-Carrier

Nature communications 7 1, 11216 (2016)

Isolators, or optical diodes, are devices enabling unidirectional light propagation by using non-reciprocal optical materials, namely materials able to break Lorentz reciprocity. The realization of isolators at terahertz frequencies is a very important open challenge made difficult by the…

Michaël Tran, Julien Levallois, Ana Akrap, Jérémie Teyssier, Alexey Kuzmenko, Florence Levy, Riccardo Tediosi, Mehdi Paul Brandt, Philippe Lerch and Dirk Van Der Marel

Review of scientific instruments 86 10, 105102 (2015)

We present an optical setup for spectroscopic measurements in the infrared and of Raman shift under high pressure and at low temperature. Using a membrane-driven diamond anvil cell, the pressure can be tuned in situ up to 20 GPa and the temperatures ranges from room temperature down to 18 K in…

Julien Levallois, Ievgeniia Nedoliuk, Iris Crassee and Alexey Kuzmenko

Review of scientific instruments 86 3, 033906 (2015)

We describe a simple magneto-optical experiment and introduce a magneto-optical Kramers-Kronig analysis (MOKKA) that together allow extracting the complex dielectric function for left- and right-handed circular polarizations in a broad range of frequencies without actually generating circularly…

Ignacio Gutierrez Lezama, Alberto Ubaldini, Maria Longobardi, Enrico Giannini, Christoph Renner, Alexey Kuzmenko and Alberto Morpurgo

2D materials 1 2, 021002 (2014)

Semiconducting transition metal dichalcogenides (TMDs) have emerged as materials that can be used to realize two-dimensional (2D) crystals possessing rather unique transport and optical properties. Most research has so far focused on sulfur and selenium compounds, while tellurium-based materials…

Nicolas Ubrig, Sanghyun Jo, Helmuth Berger, Alberto Morpurgo and Alexey Kuzmenko

Applied physics letters 104 17, 171112 (2014)

We perform scanning photocurrent microscopy on WS2 ionic liquid-gated field effect transistors exhibiting high-quality ambipolar transport. By properly biasing the gate electrode, we can invert the sign of the photocurrent showing that the minority photocarriers are either electrons or holes. Both…

Michaël Tran, Julien Levallois, Philippe Lerch, Jérémie Teyssier, Alexey Kuzmenko, G. Autès, O. V. Yazyev, Alberto Ubaldini, Enrico Giannini, Dirk Van Der Marel and Ana Akrap

Physical review letters 112 4, 047402 (2014)

BiTeI is a giant Rashba spin splitting system, in which a noncentrosymmetric topological phase has recently been suggested to appear under high pressure. We investigated the optical properties of this compound, reflectivity and transmission, under pressures up to 15 GPa. The gap feature in the…

Julien Levallois, Piotr Chudzinski, Jason Neal Hancock, Alexey Kuzmenko and Dirk Van Der Marel

Physical review. B, Condensed matter and materials physics 89 15, 155123 (2014)

We report the magnetic-field-dependent far-infrared reflectivity of polycrystalline bismuth. We observe four distinct absorptions that we attribute to magnetoplasmon resonances, which are collective modes of an electron-hole liquid in a magnetic field and become optical and acoustic resonances of…

Sanghyun Jo, Nicolas Ubrig, Helmuth Berger, Alexey Kuzmenko and Alberto Morpurgo

Nano letters 14 4, 2019-2025 (2014)

We have realized ambipolar ionic liquid gated field-effect transistors based on WS2 mono- and bilayers, and investigated their opto-electronic response. A thorough characterization of the transport properties demonstrates the high quality of these devices for both electron and hole accumulation,…

Ana Akrap, Jérémie Teyssier, Arnaud Magrez, Philippe Bugnon, Helmuth Berger, Alexey Kuzmenko and Dirk Van Der Marel

Physical review. B, Condensed matter and materials physics 90 3, 1-6 (2014)

We present a comparative study of the optical properties—reflectance, transmission, and optical conductivity—and Raman spectra of two layered bismuth-tellurohalides BiTeBr and BiTeCl at 300 and 5 K, for light polarized in the a-b planes. Despite different space groups, the optical properties of …

Jacobus Lodevicus Martinu van Mechelen, Alexey Kuzmenko and H. Merbold

Optics letters 39 13, 3853 (2014)

E Cappelluti, L Benfatto and Alexey Kuzmenko

Physica scripta T162, 014018 (2014)

Recent optical measurements in bilayer graphene have reported a strong dependence on phonon peak intensity, as well on the asymmetric Fano lineshape, on the charge doping and on the bandgap, tuned by gate voltage. In this paper, we show how these features can be analyzed and predicted on a…

Nicolas Ubrig, Iris Crassee, Julien Levallois, Ievgeniia Nedoliuk, Felix Fromm, Michl Kaiser, Thomas Seyller and Alexey Kuzmenko

Optics express 21 21, 24736-24741 (2013)

We demonstrate that giant Faraday rotation in graphene in the terahertz range due to the cyclotron resonance is further increased by constructive Fabry-Perot interference in the supporting substrate. Simultaneously, an enhanced total transmission is achieved, making this effect doubly advantageous…

Iris Crassee

Thèse (2013)

In this thesis we experimentally study the infrared magneto-optical properties of single and multilayer epitaxial graphene grown on a SiC substrate. Which is a promising material due to the scalability of the production method. However, graphene grown on SiC is also very complex, due to grain…

Jianing Chen, Maxim L. Nesterov, Alexey Yu. Nikitin, Sukosin Thongrattanasiri, Pablo Alonso-González, Tetiana M. Slipchenko, Florian Speck, Markus Ostler, Thomas Seyller, Iris Crassee, Frank H. L. Koppens, Luis Martin-Moreno, F. Javier García de Abajo, Alexey Kuzmenko and Rainer Hillenbrand

Nano letters 13 12, 6210-6215 (2013)

We employ tip-enhanced infrared near-field microscopy to study the plasmonic properties of epitaxial quasi-free-standing monolayer graphene on silicon carbide. The near-field images reveal propagating graphene plasmons, as well as a strong plasmon reflection at gaps in the graphene layer, which…

Julien Levallois, Michaël Tran and Alexey Kuzmenko

Solid state communications 152 15, 1294-1300 (2012)

We measure the far-infrared magneto-optical Kerr rotation and reflectivity spectra of graphite and achieve a highly accurate unified microscopic description of all data in abroad range of magnetic fields by taking rigorously the c-axis band dispersion and the trigonal warping in to account. We find …

Iris Crassee, M. Orlita, M. Potemski, A. L. Walter, M. Ostler, Th. Seyller, Iaroslav Gaponenko, J. Chen and Alexey Kuzmenko

Nano letters 12 5, 2470-2474 (2012)

We show that in graphene epitaxially grown on SiC the Drude absorption is transformed into a strong terahertz plasmonic peak due to natural nanoscale inhomogeneities, such as substrate terraces and wrinkles. The excitation of the plasmon modifies dramatically the magneto-optical response and in…

Nicolas Ubrig, P. Blake, Dirk Van Der Marel and Alexey Kuzmenko

Europhysics letters 100 5, 58003 (2012)

E. V. Gorbar, V. P. Gusynin, Alexey Kuzmenko and S. G. Sharapov

Physical review. B,, Condensed matter and materials physics. 86 7, 075414 (2012)

We study the influence of different kinds of gaps in a quasiparticle spectrum on longitudinal and transverse optical conductivities of bilayer graphene. An exact analytical expression for magnetooptical conductivity is derived using a low-energy two-band Hamiltonian. We consider how the layer…

M. Manzardo, E. Cappelluti, Erik Van Heumen and Alexey Kuzmenko

Physical review. B,, Condensed matter and materials physics. 86 5, 054302 (2012)

We study experimentally and theoretically the Fano-shaped phonon peak at 1590 cm−1(0.2 eV) in the in-plane optical conductivity of pristine graphite. We show that the anomalously large spectral weight and the Fano asymmetry of the peak can be qualitatively accounted for by a charged-phonon…

M Orlita, Iris Crassee, C Faugeras, Alexey Kuzmenko, F Fromm, M Ostler, Th Seyller, G Martinez, M Polini and M Potemski

New journal of physics 14 9, 095008 (2012)

We report on absolute magneto-transmission experiments on highly-doped quasi-free-standing epitaxial graphene targeting the classical-to-quantum crossover of the cyclotron resonance. This study allows us to directly extract the carrier density and also other relevant quantities such as the…

E. Cappelluti, L. Benfatto, M. Manzardo and Alexey Kuzmenko

Physical review. B, Condensed matter and materials physics 86 11, 115439 (2012)

Since their discovery, graphene-based systems represent an exceptional playground to explore the emergence of peculiar quantum effects. The present paper focuses on the anomalous appearance of strong infrared phonon resonances in the optical spectroscopy of bilayer graphene and on their pronounced…

V. K. Thorsmølle, C. C. Homes, A. Gozar, G. Blumberg, J. L. M. van Mechelen, Alexey Kuzmenko, S. Vanishri, C. Marin and H. M. Rønnow

Physical review letters 108 21, 217401 (2012)

The terahertz (THz) excitations in the quantum spin-ladder system Sr14Cu24O41 have been determined along the c axis using THz time-domain, Raman, and infrared spectroscopy. Low-frequency infrared and Raman active modes are observed above and below the charge-ordering temperature T(co) is…

Iris Crassee, Julien Levallois, Andrew L. Walter, Markus Ostler, Aaron Bostwick, Eli Rotenberg, Thomas Seyller, Dirk Van Der Marel and Alexey Kuzmenko

Nature physics 7 1, 48-51 (2011)

The rotation of the polarization of light after passing a medium in a magnetic field, discovered by Faraday, is an optical analogue of the Hall effect, which combines sensitivity to the carrier type with access to a broad energy range. Up to now the thinnest structures showing the Faraday rotation…

Iris Crassee, Julien Levallois, Dirk Van Der Marel, A. Walter, Th. Seyller and Alexey Kuzmenko

Physical review. B, Condensed matter and materials physics 84 3, 035103 (2011)

Far-infrared diagonal and Hall conductivities of multilayer epitaxial graphene on the C face of SiC were measured using magneto-optical absorption and Faraday rotation in magnetic fields up to 7 T and temperatures between 5 and 300 K. Multiple components were identified in the spectra, including…

Jason Neal Hancock, Jacobus Lodevicus Martinu van Mechelen, Alexey Kuzmenko, Dirk Van Der Marel, Christoph Brüne, Elena Novik, Georgy Astakhov, Hartmut Buhmann and Laurens Molenkamp

Physical review letters 107 13, 136803 (2011)

We present a magneto-optical study of the three-dimensional topological insulator, strained HgTe, using a technique which capitalizes on advantages of time-domain spectroscopy to amplify the signal from the surface states. This measurement delivers valuable and precise information regarding the…

Erik Van Heumen, Y. Huang, S. de Jong, Alexey Kuzmenko, M. S. Golden and Dirk Van Der Marel

Europhysics letters 90 3, 37005 (2010)

We present detailed temperature-dependent optical data on BaFe2- xCoxAs2 (BCFA), with x=0.14, between 4 meV and 6.5 eV. We analyze our spectra to determine the main optical parameters and show that in this material the interband conductivity already starts at energies as low as 10 meV. We…

E. Cappelluti, L. Benfatto and Alexey Kuzmenko

Physical review. B, Condensed matter and materials physics. 82 4, 041402 (2010)

Recent infrared measurements of phonon peaks in gated bilayer graphene reveal two striking signatures of electron-phonon interaction: an asymmetric Fano lineshape and a giant variation in the peak intensity as a function of the applied gate voltage. In this Rapid Communication we provide a unified…

S. A. Klimin, Alexey Kuzmenko, M. N. Popova, B. Z. Malkin and I. V. Telegina

Physical review. B,, Condensed matter and materials physics. 82 17, 174425 (2010)

We present infrared spectra of Gd2BaNiO5, which is isostructural to a prototype S=1 Haldane compound Y2BaNiO5 containing Ni2+ chains, in the spectral range 2 meV–0.55 eV. Unlike Y2BaNiO5, the studied compound contains magnetic rare-earth sublattices and orders antiferromagnetically at TN=58 K….

Erik Van Heumen, W Meevasana, Alexey Kuzmenko, H Eisaki and Dirk Van Der Marel

New journal of physics 11 5, 055067 (2009)

An experimental study of the in-plane optical conductivity of (Pbx,Bi2−x)(LaySr2−y)CuO6 (Bi2201) is presented for a broad doping and temperature range. The in-plane conductivity is analyzed within a strong coupling formalism. We address the interrelationship between the optical conductivity,…

Riccardo Tediosi, Fabrizio Carbone, Alexey Kuzmenko, Jérémie Teyssier, Dirk Van Der Marel and J. Mydosh

Physical review. B, Condensed matter and materials physics 80 3, 035107 (2009)

Alexey Kuzmenko, Iris Crassee, Dirk Van Der Marel, P. Blake and K. Novoselov

Physical review. B, Condensed matter and materials physics 80 16, 165406 (2009)

Alexey Kuzmenko, L Benfatto, E Cappelluti, Iris Crassee, Dirk Van Der Marel, P Blake, K. S. Novoselov and A. K. Geim

Physical review letters 103, 116804 (2009)

We observe a giant increase of the infrared intensity and a softening of the in-plane antisymmetric phonon mode Eu (∼0.2  eV) in bilayer graphene as a function of the gate-induced doping. The phonon peak has a pronounced Fano-like asymmetry. We suggest that the intensity growth and the…

Erik Van Heumen, Emmanuelle Muhlethaler, Alexey Kuzmenko, H. Eisaki, W. Meevasana, M. Greven and Dirk Van Der Marel

Physical review. B, Condensed matter and materials physics 79 18, 184512 (2009)

We take advantage of the connection between the free-carrier optical conductivity and the glue function in the normal state, to reconstruct from the infrared optical conductivity the glue spectrum of ten different high-Tc cuprates revealing a robust peak in the 50–60 meV range and a broad…

Alexey Kuzmenko, Erik Van Heumen, Dirk Van Der Marel, Philippe Lerch, P. Blake, K. S. Novoselov and A. K. Geim

Physical review. B, Condensed matter and materials physics 79 11, 115441 (2009)

We present infrared spectra (0.1–1 eV) of electrostatically gated bilayer graphene as a function of doping and compare it with tight-binding calculations. All major spectral features corresponding to the expected interband transitions are identified in the spectra: a strong peak due to…

Erik Van Heumen, Alexey Kuzmenko and Dirk Van Der Marel

Journal of physics. Conference series 150 5, 052278 (2009)

We analyze optical spectra of high temperature superconductors using a minimal model of electrons coupled to bosons. We consider the marginal Fermi liquid theory and the spin fluctuation theory, as well as a histogram representation of the bosonic spectral density. We find that the two theories can …

Alexey Kuzmenko, Erik Van Heumen, Fabrizio Carbone and Dirk Van Der Marel

Physical review letters 100 11, 117401 (2008)

We find experimentally that the optical sheet conductance of graphite per graphene layer is very close to (π/2)e2/h, which is the theoretically expected value of dynamical conductance of isolated monolayer graphene. Our calculations within the Slonczewski-Weiss-McClure model explain well why the…

F. Marsiglio, Erik Van Heumen and Alexey Kuzmenko

Physical review. B, Condensed matter and materials physics. 77 14, 144510 (2008)

A single band optical sum rule derived by Kubo can reveal a novel kind of superconducting state. It relies, however, on a knowledge of the single band contribution from zero to infinite frequency. A number of experiments over the past five years have used this sum rule; their data has been…

M. Norman, A. Chubukov, Erik Van Heumen, Alexey Kuzmenko and Dirk Van Der Marel

Physical review. B, Condensed matter and materials physics 76 22, 220509 (2007)

Much attention has been given to a possible violation of the optical sum rule in the cuprates and the connection this might have to kinetic energy lowering. The optical integral is composed of a cutoff-independent term (whose temperature dependence is a measure of the sum-rule violation), plus a…

K. Burch, S. Dordevic, F. Mena, Alexey Kuzmenko, Dirk Van Der Marel, J. Sarrao, J. Jeffries, E. Bauer, M. Maple and D. Basov

Physical review. B, Condensed matter and materials physics 75 5, 054523 (2007)

An analysis of the optical properties of heavy fermion compounds is reported. We focus on the 1-1-5 series, where strong deviations of the spectra are seen from the predictions of the periodic Anderson model. Specifically we demonstrate that the differences between the experimental results and the…

Jérémie Teyssier, Alexey Kuzmenko, Dirk Van Der Marel, Frank Marsiglio, A. Liashchenko, N. Shitsevalova and V. Filippov

Physical review. B, Condensed matter and materials physics 75 13, 134503 (2007)

We report the optical (6meV–4eV) properties of a boride superconductor ZrB12 (Tc=6K) in the normal state from 20to300K measured on high-quality single crystals by a combination of reflectivity and ellipsometry. The Drude plasma frequency and interband optical conductivity calculated by the…

Alexey Kuzmenko, Dirk Van Der Marel, Fabrizio Carbone and Frank Marsiglio

New journal of physics 9 7, 229-229 (2007)

Partial sum rules are widely used in physics to separate low- and high-energy degrees of freedom of complex dynamical systems. Their application, though, is challenged in practice by the always finite spectrometer bandwidth and is often performed using risky model-dependent extrapolations. We show…

Erik Van Heumen, Rolf Lortz, Alexey Kuzmenko, Fabrizio Carbone, Dirk Van Der Marel, X. Zhao, G. Yu, Y. Cho, N. Barisic, M. Greven, C. Homes and S. Dordevic

Physical review. B, Condensed matter and materials physics 75 5, 054522 (2007)

Alexey Kuzmenko

Physica. C, Superconductivity. 456 1-2, 63-74 (2007)

A short review of the optical and far-infrared measurements on MgB2 is given. Multiband and multigap effects are analyzed by comparing optical properties with other experiments and {\em ab initio} calculations. The covered topics are: the plasma frequency, electron-phonon interaction, impurity…

Fabrizio Carbone, Alexey Kuzmenko, Hajo Molegraaf, Erik Van Heumen, Enrico Giannini and Dirk Van Der Marel

Physical review. B, Condensed matter and materials physics 74 2, 024502 (2006)

We examine the redistribution of the in-plane optical spectral weight in the normal and superconducting state in trilayer Bi2Sr2Ca2Cu3O10 (Bi2223) near optimal doping (Tc=110K) on a single crystal via infrared reflectivity and spectroscopic ellipsometry. We report the temperature dependence of the…

Fabrizio Carbone, Alexey Kuzmenko, Hajo Molegraaf, Erik Van Heumen, Vladimir Lukovac, Frank Marsiglio, Dirk Van Der Marel, K. Haule, G. Kotliar, H. Berger, S. Courjault, P. H. Kes and M. Li

Physical review. B, Condensed matter and materials physics 74 6, 064510 (2006)

We present the ab-plane optical conductivity of four single crystals of Bi2Sr2CaCu2O8+δ(Bi2212) with different carrier doping levels from the strongly underdoped to the strongly overdoped range with Tc=66, 88, 77, and 67K, respectively. We focus on the redistribution of the low frequency optical…

Dirk Van Der Marel, Fabrizio Carbone, Alexey Kuzmenko and Enrico Giannini

Annals of physics 321 7, 1716-1729 (2006)

Violeta Guritanu, Alexey Kuzmenko, Dirk Van Der Marel, S. Kazakov, N. Zhigadlo and J. Karpinski

Physical review. B, Condensed matter and materials physics 73 10, 104509 (2006)

We present the anisotropic optical conductivity of MgB2 between 0.1 and 3.7eV at room temperature obtained on single crystals of different purity by spectroscopic ellipsometry and reflectance measurements. The bare (unscreened) plasma frequency ωp is almost isotropic and equal to 6.3eV, which…

Frank Marsiglio, Fabrizio Carbone, Alexey Kuzmenko and Dirk Van Der Marel

Physical review. B, Condensed matter and materials physics 74 17, 174516 (2006)

The Kubo single-band sum rule is used to determine the optical spectral weight of a tight-binding band with farther than nearest-neighbor hopping. We find for a wide range of parameters and doping concentrations that the change due to superconductivity at low temperature can be either negative or…

F. Mena, Alexey Kuzmenko, A. Hadipour, Jacobus Lodevicus Martinu van Mechelen, Dirk Van Der Marel and N. Babushkina

Physical review. B, Condensed matter and materials physics 72 13, 134422 (2005)

Alexey Kuzmenko, Hajo Molegraaf, Fabrizio Carbone and Dirk Van Der Marel

Physical review. B, Condensed matter and materials physics 72 14, 144503 (2005)

Alexey Kuzmenko

Review of scientific instruments 76 8, 083108 (2005)

A universal method of extraction of the complex dielectric function ϵ(ω)=ϵ1(ω)+iϵ2(ω) from experimentally accessible optical quantities is developed. The central idea is that ϵ2(ω) is parameterized independently at each node of a properly chosen anchor frequency mesh, while ϵ1(ω) is…

Alexey Kuzmenko, N. Tombros, F.P. Mena, A. Hadipour, H.J.A. Molegraaf, Dirk Van Der Marel, M. Grüninger and S. Uchida

Physica. C, Superconductivity 408-410, 330-331 (2004)

Optical transmission measurements provide a detailed picture of redistribution of the c-axis spectral weight of La2−xSrxCuO4 (x=0.12, 0.15) and allows to examine the Ferrell–Glover–Tinkham (FGT) sum rule up to 1.8 eV. A new conductivity peak is observed below Tc at ∼120 meV, which indicates …

Alexey Kuzmenko, N. Tombros, H. J. A. Molegraaf, M. Grüninger, Dirk Van Der Marel and S. Uchida

Physical review letters 91 3, 037004 (2003)

We present the c -axis optical conductivity σ 1 c ( ω , T ) of underdoped ( x = 0.12 ) and optimally doped ( x = 0.15 ) L a 2 − x S r x C u O 4 from 4 meV to 1.8 eV obtained by a combination of reflectivity and transmission spectra. In addition to the opening of the superconducting gap, we…

Alexey Kuzmenko, F.P. Mena, H.J.A. Molegraaf, Dirk Van Der Marel, B. Gorshunov, M. Dressel, I.I. Mazin, J. Kortus, O.V. Dolgov, T. Muranaka and J. Akimitsu

Solid state communications 121 9-10, 479-484 (2002)

The optical conductivity of MgB2 has been determined on a dense polycrystalline sample in the spectral range 6 meV–4.6 eV using a combination of ellipsometric and normal incidence reflectivity measurements. σ1(ω) features a narrow Drude peak with anomalously small plasma frequency (1.4 eV) and…

I. I. Mazin, O. K. Andersen, O. Jepsen, O. V. Dolgov, J. Kortus, A. A. Golubov, Alexey Kuzmenko and Dirk Van Der Marel

Physical review letters 89 10, 107002 (2002)

A large number of experimental facts and theoretical arguments favor a two-gap model for superconductivity in M g B 2 . However, this model predicts strong suppression of the critical temperature by interband impurity scattering and, presumably, a strong correlation between the critical temperature …

A. A. Bush, V. Ya. Shkuratov, Alexey Kuzmenko and E. A. Tishchenko

Crystallography reports 47 2, 335-339 (2002)

Experiments on the growth of CuO single crystals by crystallization from flux in the CuO–Bi2O3– PbO–PbF2, CuO–Bi2O3–Li2O, CuO–Bi2O3–B2O3, CuO–BaO–Y2O3, and CuO–MOx systems (M = P, V, or Mo) have been performed. The best results were obtained in crystallization in the…

J. W. van der Eb, Alexey Kuzmenko and Dirk Van Der Marel

Physical review letters 86 15, 3407-3410 (2001)

We determined the optical properties of α – and γ -phase Ce in the photon energy range from 60 meV to 2.5 eV using ellipsometry and grazing incidence reflectometry. We observe significant changes of the optical conductivity, the dynamical scattering rate, and the effective mass between α – and…

B. Gorshunov, C.A. Kuntscher, P. Haas, M. Dressel, F.P. Mena, Alexey Kuzmenko, Dirk Van Der Marel, T. Muranaka and J. Akimitsu

The European physical journal. B., Condensed matter physics. 21 2, 159-161 (2001)

Far-infrared reflectivity studies on the polycrystalline intermetallic compound MgB_2 with a superconducting transition temperature T_c=39 K were performed at temperatures 20 K to 300 K. We observe a significant raise of the superconducting-to-normal state reflectivity ratio below 70 cm^{-1}, with…

Alexey Kuzmenko, Dirk Van Der Marel, P.J.M van Bentum, E.A Tishchenko, C Presura and A.A Bush

Physica. B, Condensed matter 284-288, 1396-1397 (2000)

We report the “rst measurements of FIR and MIR re#ectivity of single-crystal monoclinic antiferromagnetic copper monoxide (CuO) in a wide temperature range (7}300 K) when b-axis and ac-plane polarized modes are completely separated and excited in transverse geometry. Previously reported softening…

Alexey Kuzmenko, E. A. Tishchenko and A.S. Krechetov

Optics and spectroscopy 84, 402-409 (1998)

An extension of the Kramers-Kronig method for treatment of polarized infrared reflectance spectra from the face of low-symmetry crystals, where directions of principal dielectric axes depend on frequency, is proposed. It is shown, how to obtain the frequency dependencies of the complex reflectivity …

Alexey Kuzmenko, E A Tishchenko and V G Orlov

Journal of physics. Condensed matter. 8 34, 6199-6212 (1996)

Measurements of infrared polarized reflectance spectra of single-crystal α-Bi2O3 have been made at room temperature in the wavelength range from 30 to 4000 cm−1 for different orientations of the wave vector k and the electric field E of the incident radiation relative to the crystallographic…

Alexey Kuzmenko, E. A. Tishchenko, A. N. Ivlev and V. G. Orlov

Czechoslovak Journal of Physics 46 S5, 2665-2666 (1996)

Polarized IR reflectance spectra of monoclinic single crystal ~-Bi20 ~ for different directions of the wave vector k and the electric field E of the incident radiation have been measured in a wide temperature range (25-400 K). A significant dependence of the spectrum shape on the direction of the…

Alexey Kuzmenko, E. A. Tishchenko, I. L. Sashin, M. N. Khlopkin and V. G. Orlov

Journal of low temperature physics 105 3-4, 861-866 (1996)

Studies on the lattice dynamics of ct-Bi203 have been performed including IR polarized reflectance spectra on single crystal, inelastic neutron scattering and specific heat measurements. Dispersion parameters and polarizations of IRactive phonons are presented and compared with neutron and specific …