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Related papers: Excitonic Mott transition in type-II quantum dots

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Second order perturbation theory and a Lipkin-Nogami scheme combined with an exact Monte Carlo projection after variation are applied to compute the ground-state energy of $6\le N\le 210$ electron-hole pairs confined in a parabolic…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Boris A. Rodriguez , Augusto Gonzalez , Luis Quiroga , Roberto Capote , Ferney Rodriguez

Exciton Mott transition in Si is investigated by using terahertz time-domain spectroscopy. The excitonic correlation as manifested by the 1s-2p resonance is observed above the Mott density. The scattering rate of charge carriers is…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 Takeshi Suzuki , Ryo Shimano

Superfluidity of spatially separated electrons and holes and unbalanced two-layer electron system in high magnetic field is considered. The temperature of the Kosterlitz-Thouless transition to a superfluid state is obtained as a function of…

Condensed Matter · Physics 2016-08-31 Yu. E. Lozovik , O. L. Berman , V. G. Tsvetus

Excitons in vertically stacked type-II quantum dots experience the topological magnetic phase and demonstrate the Aharonov-Bohm oscillations in the emission intensity. Photoluminescence of vertically stacked ZnTe/ZnSe quantum dots is…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Igor L Kuskovsky , W. MacDonald , A. O. Govorov , L. Muroukh , X. Wei , M. C. Tamargo , M. Tadic , F. M. Peeters

We describe the ground state of a gas of bosonic atoms with two coherently coupled internal levels in a deep optical lattice in a one dimensional geometry. In the single-band approximation this system is described by a Bose-Hubbard…

Quantum Gases · Physics 2016-03-29 L. Barbiero , M. Abad , A. Recati

The elementary optical excitations in two dimensional semiconductors hosting itinerant electrons are attractive and repulsive polarons -- excitons that are dynamically screened by electrons. Exciton-polarons have hitherto been studied in…

Excitons in semiconductors may form correlated phases at low temperatures. We report the observation of an exciton liquid in GaAs/AlGaAs coupled quantum wells. Above a critical density and below a critical temperature the photogenerated…

Mesoscale and Nanoscale Physics · Physics 2015-03-13 Michael Stern , Vladimir Umansky , Israel Bar-Joseph

We have performed time-resolved terahertz absorption measurements on photoexcited electron-hole pairs in undoped GaAs quantum wells in magnetic fields. We probed both unbound- and bound-carrier responses via cyclotron resonance and…

Two dimensional materials and their heterostructures constitute a promising platform to study correlated electronic states as well as many body physics of excitons. Here, we present experiments that unite these hitherto separate efforts and…

Mesoscale and Nanoscale Physics · Physics 2020-05-12 Yuya Shimazaki , Ido Schwartz , Kenji Watanabe , Takashi Taniguchi , Martin Kroner , Ataç Imamoğlu

The photoluminescence (PL) of a two-dimensional electron gas (2DEG) in a high magnetic field is studied as a function of the filling factor and the separation d between the electron layer and the valence hole. Depending on the magnitude of…

Mesoscale and Nanoscale Physics · Physics 2015-06-24 Arkadiusz Wojs

By combining electron energy-loss spectroscopy and state-of-the-art computational methods, we were able to provide an extensive picture of the excitonic processes in $1T$-HfS$_2$. The results differ significantly from the properties of the…

Mesoscale and Nanoscale Physics · Physics 2018-10-17 Carsten Habenicht , Lorenzo Sponza , Roman Schuster , Martin Knupfer , Bernd Büchner

Mostly, optical spectroscopies are used to investigate the physics of excitons, whereas their electrical evidences are hardly explored. Here, we examined a forward bias activated differential capacitance response of GaInP-AlGaInP based…

Mesoscale and Nanoscale Physics · Physics 2016-10-21 Amit Bhunia , Kanika Bansal , Mohamed Henini , Marzook S. Alshammari , Shouvik Datta

We present an InAs-GaSb-based system in which the electric-field tunability of its 2D energy gap implies a transition towards a thermodynamically stable excitonic condensed phase. Detailed calculations show a 3 meV BCS-like gap appearing in…

Condensed Matter · Physics 2009-10-28 Y. Naveh , B. Laikhtman

We report on a magneto-photoluminescence study of isotopically pure 70Ge/Si self-assembled type-II quantum dots. Oscillatory behaviors attributed to the Aharonov-Bohm effect are simultaneously observed for the emission energy and intensity…

We have used magneto-photoluminescence measurements to establish that InP/GaAs quantum dots have a type-II (staggered) band alignment. The average excitonic Bohr radius and the binding energy are estimated to be 15nm and 1.5 meV…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 Bhavtosh Bansal , S. Godefroo , M. Hayne , G. Medeiros- Ribeiro , V. V. Moshchalkov

Excitons are two-particle correlated bound states that are formed due to Coulomb interaction between single-particle holes and electrons. In the solid-state, cooperative interactions with surrounding quasiparticles can strongly tailor the…

The demonstration of degeneracy of the exciton spin states is an important step towards the production of entangled photons pairs from the biexciton cascade. We measure the fine structure of exciton and biexciton states for a large number…

In a quantum dot with dozens of electrons, an approximation beyond Tamm-Dankoff is used to construct the quantum states with an additional electron-hole pair, i.e. the "excitonic" states. The lowest states mimic the non-interacting…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Alexander Odriazola , Alain Delgado , Augusto Gonzalez

Recently we reported on the condensation of cold, electrostatically trapped dipolar excitons in GaAs bilayer heterostructure into a new, dense and dark collective phase. Here we analyze and discuss in detail the experimental findings and…

Quantum Gases · Physics 2017-04-04 Yotam Mazuz-Harpaz , Kobi Cohen , Ronen Rapaport

Charged magneto-excitons X- in a dilute 2D electron gas in narrow and symmetric quantum wells are studied using exact diagonalization techniques. An excited triplet X- state with a binding energy of about 1 meV is found. This state and the…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Arkadiusz Wojs , John J. Quinn , Pawel Hawrylak