Publications associées à Polarization of exciton-polariton condensates in lateral traps

Exciton migration in two-dimensional materials

Excitons play an essential role in the optical response of two-dimensional materials. These are bound states showing up in the band gaps of many-body systems and are conceived as quasiparticles formed by an electron and a hole. By performing real-time simu ...

Nature Portfolio2024

Ultralong 100 ns spin relaxation time in graphite at room temperature

László Forró, Bálint Náfrádi, Péter Szirmai, Bence Gábor Márkus

Graphite has been intensively studied, yet its electron spins dynamics remains an unresolved problem even 70 years after the first experiments. The central quantities, the longitudinal (T-1) and transverse (T-2) relaxation times were postulated to be equal ...

Nature Portfolio2023

A versatile platform for graphene nanoribbon synthesis, electronic decoupling, and spin polarized measurements

Donat Fabian Natterer, Johannes Schwenk

The on-surface synthesis of nano-graphenes has led the charge in prototyping structures with perspectives beyond silicon-based technology. Following reports of open-shell systems in graphene-nanoribbons (GNRs), a flurry of research activity was directed at ...

ROYAL SOC CHEMISTRY2023

Optoelectronics based on the spin-valley physics of 2D materials

Juan Francisco Gonzalez Marin

Two-dimensional (2D) materials are atomically thin crystals with exceptional mechanical, electrical and optical properties. Their unique characteristics originating from quantum confinement in the vertical dimension have attracted a strong interest for sci ...

EPFL2022

Near-field probing of image phonon-polaritons in hexagonal boron nitride on gold crystals

Sergejs Boroviks

Near-field mapping has been widely used to study hyperbolic phonon-polaritons in van der Waals crystals. However, an accurate measurement of the polaritonic loss remains challenging because of the inherent complexity of the near-field signal and the substr ...

AMER ASSOC ADVANCEMENT SCIENCE2022

Low-Loss Anisotropic Image Polaritons in van der Waals Crystal alpha-MoO3

Sergejs Boroviks

Orthorhombic molybdenum trioxide (alpha-MoO3), a newly discovered polaritonic van der Waals crystal, is attracting significant attention due to its strongly anisotropic mid-infrared phonon-polaritons. At the same time, coupling of polariton with its mirror ...

WILEY-V C H VERLAG GMBH2022

Nanophotonic biosensors harnessing van der Waals materials

Hatice Altug

Low-dimensional van der Waals (vdW) materials can harness tightly confined polaritonic waves to deliver unique advantages for nanophotonic biosensing. The reduced dimensionality of vdW materials, as in the case of two-dimensional graphene, can greatly enha ...

Nature Research2021

Polaritonic Cross Feshbach Resonance

Daniel Oberli, Marcia Portella Oberli, Naotomo Takemura, Mitchell David Anderson, Morteza Navadeh Toupchi

We demonstrate the existence of a cross Feshbach resonance by strongly driving a lower polariton mode and by monitoring in time the transmission of a short optical pulse at the energy of the upper polariton mode in a semiconductor microcavity. From the sig ...

2019

Crystalline and correlated phases in two-dimensional transition metal dichalcogenides

Diego José Pasquier

This thesis is dedicated to the study of various aspects of the electronic structure of two-dimensional transition metal dichalcogenides (TMDs) of chemical composition MX

_2

(where M is a transition metal atom and X= S, Se, Te), using a combination of \te ...

EPFL2019

Light-Matter Interaction in III-Nitride Waveguides: Propagating Polaritons and Optical Gain

Joachim Armand Simonne Ciers

III-nitride waveguides featuring AlInN claddings and GaN/AlGaN quantum wells (QWs) offer promising perspectives for applications in many fields of short-wavelength photonics. Thanks to their nearly lattice-matched nature, these structures exhibit an excell ...

EPFL2018

Excitonic effects in two-dimensional TiSe2 from hybrid density functional theory

Oleg Yazyev, Diego José Pasquier

Transition metal dichalcogenides (TMDs), whether in bulk or in monolayer form, exhibit a rich variety of charge-density-wave (CDW) phases and stronger periodic lattice distortions. While the actual role of nesting has been under debate, it is well understo ...

AMER PHYSICAL SOC2018

Phonon-Driven Selective Modulation of Exciton Oscillator Strengths in Anatase TiO2Nanoparticles

Majed Chergui, Gerald Auböck, Thomas Charles Henry Rossi, Tania Palmieri, Edoardo Baldini, Enrico Pomarico, Malte Oppermann

The way nuclear motion affects electronic responses has become a very hot topic in materials science. Coherent acoustic phonons can dynamically modify optical, magnetic, and mechanical properties at ultrasonic frequencies, with promising applications as se ...

American Chemical Society (ACS)2018

Anomalous anisotropic exciton temperature dependence in rutile TiO2

Majed Chergui, Edoardo Baldini

Elucidating the details of electron-phonon coupling in semiconductors and insulators is a topic of pivotal interest, as it governs the transport mechanisms and is responsible for various phenomena such as spectral-weight transfers to phonon sidebands and s ...

2017

Microscopic Origin of the Valley Hall Effect in Transition Metal Dichalcogenides Revealed by Wavelength-Dependent Mapping

Helmuth Berger

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 tr ...

Amer Chemical Soc2017

Spin-resolved photoemission study of epitaxially grown MoSe2 and WSe2 thin films

Zahid Hussain, Stefan Peter Muff, Jan Hugo Dil, Mauro Fanciulli, Yi Zhang

Few-layer thick MoSe2 and WSe2 possess non-trivial spin textures with sizable spin splitting due to the inversion symmetry breaking embedded in the crystal structure and strong spin-orbit coupling. We report a spin-resolved photoemission study of MoSe2 and ...

Institute of Physics2016

Nonlocal electromagnetic response of graphene nanostructures

Julien Perruisseau-Carrier, Michele Tamagnone

Nonlocal electromagnetic effects of graphene arise from its naturally dispersive dielectric response. We present semianalytical solutions of nonlocal Maxwell's equations for graphene nanoribbon arrays with features around 100 nm, where we found prominent d ...

Amer Physical Soc2015

Noise-Induced Phenomena in Collective Spinor Polariton Excitations

Hadis Abbaspour

Polaritons are quasiparticles resulting from the strong coupling between photons and excitons embedded in a semiconductor microcavity. The exciton component of polaritons provides strong nonlinear interactions, while their photonic counterpart facilitates ...

EPFL2015

Investigation of interactions in two-dimensional electron gases with angular resolved photoemission spectroscopy

Carola Strasser

In this thesis, angular resolved photoemission spectroscopy (ARPES) is used to study the electronic structure of different two-dimensional electron systems (2DES). This technique is very surface sensitive and the most direct method to probe the surface ban ...

EPFL2015

Fundamental limits and near-optimal design of graphene modulators and non-reciprocal devices

Juan Ramon Mosig, Julien Perruisseau-Carrier, Michele Tamagnone

The potential of graphene for photonic applications was evidenced by recent demonstrations of modulators, polarization rotators and isolators. These promising yet preliminary results raise crucial questions: what is the optimal performance achievable by mo ...

Nature Publishing Group2014

Heterodyne spectroscopy of polariton spinor interactions

Benoît Marie Joseph Deveaud, Marcia Portella Oberli, Stéphane Trebaol, Naotomo Takemura

We report on spinor polariton interactions in GaAs based microcavities. This investigation is carried out by means of heterodyne polarized pump-probe spectroscopy. We show the dependence of the energy renormalization of the lower and upper polariton resona ...

American Physical Society2014