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In a GaAs single quantum dot, the relaxation time T_{1} between spin triplet and singlet states has been measured for the last few even number of electrons. The singlet-triplet energy separation E_{ST} is tuned as a control parameter for…

Mesoscale and Nanoscale Physics · Physics 2012-05-08 Gang Cao , Ming Xiao , HaiOu Li , Tao Tu , GuoPing Guo

We present Coulomb Blockade measurements of two few-electron quantum dots in series which are configured such that the electrochemical potential of one of the two dots is aligned with spin-selective leads. The charge transfer through the…

Mesoscale and Nanoscale Physics · Physics 2016-08-16 M. Ciorga , M. Pioro-Ladrière , P. Zawadzki , J. Lapointe , Z. Wasilewski , A. S. Sachrajda

We consider a triple quantum dot system in a triangular geometry with one of the dots connected to metallic leads. Using Wilson's numerical renormalization group method, we investigate quantum entanglement and its relation to the…

Strongly Correlated Electrons · Physics 2015-06-15 S. B. Tooski , A. Ramsak , R. Zitko , B. R. Bulka

We report the observation of an unusually large number of consecutive spin pairs in a weakly coupled many-electron GaAs/AlGaAs quantum dot. The pairs are identified due to pairwise parallel shifts of Coulomb resonances in a perpendicular…

Mesoscale and Nanoscale Physics · Physics 2015-09-29 S. Hellmüller , D. Bischoff , T. Müller , M. Beck , K. Ensslin , T. Ihn

The electronic structure of InAs/AlSb/GaSb quantum wells embedded in AlSb barriers and in the presence of a perpendicular magnetic field is studied theoretically within the $14$-band ${\bf k}\cdot{\bf p}$ approach without making the axial…

Materials Science · Physics 2015-09-30 X. G. Wu , M. Pang

We quantify the contributions of hyperfine and spin-orbit mediated singlet-triplet mixing in weakly coupled InAs quantum dots by electron transport spectroscopy in the Pauli spin blockade regime. In contrast to double dots in GaAs, the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 A. Pfund , I. Shorubalko , K. Ensslin , R. Leturcq

We propose a theoretical model of quasi-one-dimensional superconductors, with attractive electron-electron interactions dominant in the singlet d-wave channel and sub-dominant in the p-wave channel. We discuss, in the mean field…

Strongly Correlated Electrons · Physics 2007-12-04 N. Belmechri , G. Abramovici , M. Heritier , S. Haddad , S. Kaddour

Spin-orbit coupling effects are studied in quantum dots in InSb, a narrow-gap material. Competition between different Rashba and Dresselhaus terms is shown to produce wholesale changes in the spectrum. The large (and negative) $g$-factor…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 C. F. Destefani , S. E. Ulloa , G. E. Marques

We report inelastic light scattering measurements of spin and charge excitations in nanofabricated AlGaAs/GaAs quantum dots with few electrons. A narrow spin excitation peak is observed and assigned to the intershell triplet-to-singlet…

We study electronic configurations in a single pair of vertically coupled self-assembled InAs quantum dots, holding just a few electrons. By comparing the experimental data of non-linear single-electron transport spectra in a magnetic field…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 T. Ota , M. Rontani , S. Tarucha , Y. Nakata , H. Z. Song , T. Miyazawa , T. Usuki , M. Takatsu , N. Yokoyama

We analyze cotunneling transport through two quantum dots in series weakly coupled to external ferromagnetic leads. In the Coulomb blockade regime the electric current flows due to third-order tunneling, while the second-order…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 I. Weymann

Three terminal tunnelling experiments on quantum dots in the Coulomb blockade regime allow a quantitative determination of the coupling strength of individual quantum states to the leads. Exploiting this insight we have observed independent…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 R. Leturcq , D. Graf , T. Ihn , K. Ensslin , D. D. Driscoll , A. C. Gossard

We present a theory of electronic properties and the spin blockade phenomena in a gated linear triple quantum dot. Quadruple points where four different charge configurations are on resonance, particularly involving (1,1,1) configuration,…

Mesoscale and Nanoscale Physics · Physics 2015-05-30 Chang-Yu Hsieh , Yun-Pil Shim , Pawel Hawrylak

We investigate the energy spectra of three electrons in SiGe/Si/SiGe equilateral triangular and symmetric linear triple quantum dots in the presence of magnetic (in either Faraday or Voigt configuration) and electric fields with single…

Mesoscale and Nanoscale Physics · Physics 2014-07-22 Y. F. Ren , L. Wang , Z. Liu , M. W. Wu

Equilibrium properties of electrons in double-heterojunction AlGaAs/GaAs\AlGaAs structures are investigated theoretically, using a full self-consistent numerical method. The transition from single to bilayer electron systems is discussed…

Condensed Matter · Physics 2016-08-31 L. Smrcka , T. Jungwirth

We investigate transport properties of stable gate-defined quantum dots formed in an InSb$_{0.87}$As$_{0.13}$ quantum well. High $\textit{g}$-factor and strong spin-orbit-coupling make InSb$_x$As$_{1-x}$ a promising platform for exploration…

Mesoscale and Nanoscale Physics · Physics 2023-11-13 S. Metti , C. Thomas , M. J. Manfra

The total spin of correlated electrons in a quantum dot changes with magnetic field and this effect is generally linked to the change in the total angular momentum from one magic number to another, which can be understood in terms of an…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 Hiroshi Imamura , Hideo Aoki , Peter A. Maksym

Kondo effect in the vicinity of a singlet-triplet transition in a vertical quantum dot is considered. This system is shown to map onto a special version of the two-impurity Kondo model. At any value of the control parameter, the system has…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 M. Pustilnik , L. I. Glazman

We present transport measurements through an electrostatically defined bilayer graphene double quantum dot in the single electron regime. With the help of a back gate, two split gates and two finger gates we are able to control the number…

Mesoscale and Nanoscale Physics · Physics 2020-04-22 Luca Banszerus , Samuel Möller , Eike Icking , Kenji Watanabe , Takashi Taniguchi , Christian Volk , Christoph Stampfer

In-plane magnetic field photoluminescence spectra from a series of GaAs/AlGaAs coupled double quantum wells show distinctive doublet structures related to the symmetric and antisymmetric states. The magnetic field behavior of the upper…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Yongmin Kim , C. H. Perry , J. A. Simmons