Publications de Daniel Oberli | EPFL Graph Search

Localized Photon Lasing in a Polaritonic Lattice Landscape

Daniel Oberli, Marcia Portella Oberli, Fauzia Jabeen, Morteza Navadeh Toupchi

Periodic photonic structures have attracted much interest due to their versatility for controlling light propagation. The dispersion of photon modes in photonic lattices exhibits an energy band structure analo-gous to the electronic one in crystals. An imp ...

American Physical Society (APS)2020

Anderson localisation in steady states of microcavity polaritons

Daniel Oberli, Marcia Portella Oberli, Fauzia Jabeen, Albert Adiyatullin, Mitchell David Anderson, Morteza Navadeh Toupchi

We present an experimental signature of the Anderson localisation of microcavity polaritons, and provide a systematic study of the dependence on disorder strength. We reveal a controllable degree of localisation, as characterised by the inverse-participati ...

Springer Nature2019

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

Reservoir-induced decoherence of resonantly excited confined polaritons

Benoît Marie Joseph Deveaud, François Morier-Genoud, Daniel Oberli, Marcia Portella Oberli, Grégory Chilpéric Sallen, Claudéric Ouellet-Plamondon

We report on the effect of decoherence on polariton bistability. The polariton hysteresis loop is shown to collapse in a similar way when increasing the temperature or under nonresonant excitation power. The hysteresis upward threshold is pulled to lower e ...

Amer Physical Soc2017

Spatial multistability induced by cross interactions of confined polariton modes

Benoît Marie Joseph Deveaud, François Morier-Genoud, Daniel Oberli, Marcia Portella Oberli, Grégory Chilpéric Sallen, Claudéric Ouellet-Plamondon

We demonstrate the occurrence of spatial multistability using laterally confined microcavity exciton-polaritons. By coherently exciting with a blue detuned laser a series of confined polariton modes, we investigate the effects of multistability on the tran ...

Amer Physical Soc2016

Coherent and incoherent aspects of polariton dynamics in semiconductor microcavities

Benoît Marie Joseph Deveaud, Daniel Oberli, Marcia Portella Oberli, Naotomo Takemura, Mitchell David Anderson, Morteza Navadeh Toupchi, Souvik Biswas

The interaction between coherent polaritons and incoherent excitons plays an important role in polariton physics. Using resonant pump-probe spectroscopy with selective excitation of single polariton branches, we investigate the different dephasing mechanis ...

Amer Physical Soc2016

Two-dimensional Fourier transform spectroscopy of exciton-polaritons and their interactions

Benoît Marie Joseph Deveaud, Daniel Oberli, Marcia Portella Oberli, Verena Kohnle, Stéphane Trebaol, Naotomo Takemura, Mitchell David Anderson

We investigate polariton-polariton interactions in a semiconductor microcavity through two-dimensional Fourier transform (2DFT) spectroscopy. We observe, in addition to the lower-lower and the upper-upper polariton self-interactions, a lower-upper cross in ...

American Physical Society2015

Dephasing effects on coherent exciton-polaritons and the breakdown of the strong coupling regime

Benoît Marie Joseph Deveaud, Daniel Oberli, Marcia Portella Oberli, Stéphane Trebaol, Naotomo Takemura, Mitchell David Anderson, Souvik Biswas

Using femtosecond pump-probe spectroscopy, we identify excitation-induced dephasing as a major mechanism responsible for the breakdown of the strong coupling between excitons and photons in a semiconductor microcavity. The effects of dephasing are observed ...

American Physical Society2015

Multiple polariton modes originating from the coupling of quantum wells in planar microcavity

Benoît Marie Joseph Deveaud, Daniel Oberli, Grégory Chilpéric Sallen, Claudéric Ouellet-Plamondon, Fauzia Jabeen

We report on the observation of multiple polariton modes, originating from an electronic coupling between quantum wells inside a planar microcavity. A series of excitonic transitions are measured for a bare quantum well stack and are precisely identified t ...

American Physical Society2015

Spectral signatures of high-symmetry quantum dots and effects of symmetry breaking

Marc-André Dupertuis, Elyahou Kapon, Daniel Oberli, Alok Rudra, Valentina Troncale

High symmetry epitaxial quantum dots (QDs) with three or more symmetry planes provide a very promising route for the generation of entangled photons for quantum information applications. The great challenge to fabricate nanoscopic high symmetry QDs is furt ...

Iop Publishing Ltd2015

Nanostructure Symmetry: Relevance for Physics and Computing

Marc-André Dupertuis, Daniel Oberli, Sascha Dalessi, Benjamin Gallinet

We review the research done in recent years in our group on the effects of nanostructure symmetry, and outline its relevance both for nanostructure physics and for computations of their electronic and optical properties. The exemples of C3v and C2v quantum ...

Amer Inst Physics2014

Functionalized graphene grown by oxidative dehydrogenation chemistry

László Forró, Daniel Oberli, Arnaud Magrez, Arnaud Walter, Jacim Jacimovic, Massimo Spina, Endre Horvath, Laurent Syavoch Bernard

We report on a highly efficient growth of graphene using dehydrogenation of acetylene by an oxidative reaction with carbon dioxide. In few seconds, large-area of copper foil used as catalyst of the reaction is fully covered with graphene. The yield of the ...

Pergamon-Elsevier Science Ltd2014

Intertwining of Zeeman and Coulomb interactions on excitons in highly symmetric semiconductor quantum dots

Daniel Oberli

We present an experimental study and develop a group theoretical analysis of the Zeeman effect on excitons in pyramidal semiconductor quantum dots possessing the symmetries of the C3v point group. The magnetic field dependence of the emission pattern origi ...

2012

Symmetries and the Polarized Optical Spectra of Exciton Complexes in Quantum Dots

Marc-André Dupertuis, Elyahou Kapon, Daniel Oberli, Alok Rudra

A systematic and simple theoretical approach is proposed to analyze true degeneracies and polarized decay patterns of exciton complexes in semiconductor quantum dots. The results provide reliable spectral signatures for efficient symmetry characterization, ...

2011

Symmetry Elevation and Symmetry Breaking: Keys to Describe and Explain Excitonic Complexes in Semiconductor Quantum Dots

Marc-André Dupertuis, Elyahou Kapon, Daniel Oberli, Alok Rudra

The results of a group theoretical analysis of the excitonic fine structure are presented and compared with spectroscopic data on single quantum dots. The spectral features reveal the signatures of a symmetry higher than the crystal symmetry (C-3v). A cons ...

Amer Inst Physics, 2 Huntington Quadrangle, Ste 1No1 D, Melville, Ny 11747-4501 Usa2011

Fine structure of exciton complexes in high-symmetry quantum dots: Effects of symmetry breaking and symmetry elevation

Marc-André Dupertuis, Elyahou Kapon, Daniel Oberli, Alok Rudra

Quantum dots (QDs) of high symmetry (e.g., C3v) have degenerate bright exciton states, unlike QDs of C2v symmetry, making them intrinsically suitable for the generation of entangled photon pairs. Deviations from C3v symmetry are detected in real QDs by pol ...

American Physical Society2010

Magneto-Optical Spectroscopy Of Charged Excitonic States In Quantum Dots: Evidence Of Quantum Correlation

Elyahou Kapon, Daniel Oberli, Alok Rudra

Iop Publishing Ltd, Dirac House, Temple Back, Bristol Bs1 6Be, England2010

Coulomb correlations of charged excitons in semiconductor quantum dots

Elyahou Kapon, Daniel Oberli, Alok Rudra

The emission pattern of charged excitons in a semiconductor quantum dot (QD) is composed of a quadruplet of linearly polarized lines when a magnetic field is applied in a Voigt configuration. The orientation of the linear polarization of exciton emission i ...

2009

Narrow inhomogeneous broadening of V-groove quantum wires grown on vicinal substrates

Benjamin Dwir, Elyahou Kapon, Daniel Oberli, Alok Rudra, Nicolas Moret, Pascal Gallo

Significant reduction in inhomogeneous broadening of GaAs/AlGaAs V- groove quantum wires (QWRs) is achieved by growing them on vicinal (001) GaAs substrates misaligned by several degrees with respect to the [1 (1) over bar0] groove direction. Low temperatu ...

American Institute of Physics2008

Excited excitonic states observed in semiconductor quantum dots using polarization resolved optical spectroscopy

Elyahou Kapon, Daniel Oberli, Alok Rudra, Valentina Troncale

We present results on the polarization-resolved photoluminescence emitted from InGaAs/AlGaAs single quantum dots (QDs) grown in inverted tetrahedral pyramids. The emitted light was detected for two mutually perpendicular linear polarization directions in t ...

American Institute of Physics2007