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Related papers: Multipole excitations in quantum dots

200 papers

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 carrier spin dynamics in a n-doped (In,Ga)As/GaAs quantum well has been studied by time-resolved Faraday rotation and ellipticity techniques in the temperature range down to 430 milliKelvin. These techniques give data with very…

Mesoscale and Nanoscale Physics · Physics 2010-09-15 L. V. Fokina , I. A. Yugova , D. R. Yakovlev , M. M. Glazov , I. A. Akimov , A. Greilich , D. Reuter , A. D. Wieck , M. Bayer

We investigate different types of collective excitations in a quantum dot containing finite number of electrons at zero magnetic field. To estimate the excitation energies analytically we follow the energy weighted sum-rule approach. We…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Subhasis Sinha

We present a microscopic theory for transport of the spin polarized charge density wave with both electrons and holes in the $(111)$ GaAs quantum wells. We analytically show that, contradicting to the commonly accepted belief, the spin and…

Mesoscale and Nanoscale Physics · Physics 2013-11-27 M. Q. Weng , M. W. Wu

We investigate the spin of a multielectron GaAs quantum dot in a sequence of nine charge occupancies, by exchange coupling the multielectron dot to a neighboring two-electron double quantum dot. For all nine occupancies, we make use of a…

We study the spin-dependent electronic excitations in alkali-metal nanoparticles. Using numerical and analytical approaches, we focus on the resonances in the response to spin-dependent dipole fields. In the spin-dipole absorption spectrum…

Mesoscale and Nanoscale Physics · Physics 2009-09-18 Yue Yin , Paul-Antoine Hervieux , Rodolfo A. Jalabert , Giovanni Manfredi , Emmanuel Maurat , Dietmar Weinmann

Quantized spin excitations in a single ferromagnetic microstrip have been measured using the microwave photovoltage technique. Several kinds of spin wave modes due to different contributions of the dipole-dipole and the exchange…

Strongly Correlated Electrons · Physics 2009-11-13 Y. S. Gui , N. Mecking , C. -M. Hu

Quantum Hall edge excitations, whose low-energy behavior admits a chiral conformal-field-theory description, are a promising platform for engineered dynamical experiments, including analog-spacetime proposals. However, establishing their…

Mesoscale and Nanoscale Physics · Physics 2026-04-01 Yunhyeon Jeong , Akinori Kamiyama , John N. Moore , Takaaki Mano , Ken-ichi Sasaki , Yuuki Sugiyama , Tokiro Numasawa , Masahiro Hotta , Go Yusa

Excitation of spin wave modes of a vortex-state magnetic dot by an out-of-plane oscillating magnetic field is studied numerically in the presence of a static in-plane magnetic field. It is shown, that the application of the in-plane static…

Mesoscale and Nanoscale Physics · Physics 2016-04-26 Yan Liu , Yan Zhou , P. Dürrenfeld , Y. Yin , D. W. Wang , A. N. Slavin , A. Ruotolo

A quantum kinetic theory is used to compute excitation induced dephasing in semiconductor quantum dots due to the Coulomb interaction with a continuum of states, such as a quantum well or a wetting layer. It is shown that a frequency…

Materials Science · Physics 2009-11-10 H. C. Schneider , W. W. Chow , S. W. Koch

Mott insulators with localized magnetic moments will exhibit a quantum spin liquid (QSL) state when the quantum fluctuations are strong enough to suppress the ordering of the spins. Such an entangled state will give rise to collective…

Strongly Correlated Electrons · Physics 2025-04-17 Haiyang Chen , Fo-Hong Wang , Qiang Gao , Xue-Jian Gao , Zhenhua Chen , Yaobo Huang , Kam Tuen Law , Xiao Yan Xu , Peng Chen

We derive the random-phase approximation for spin excitations in general multi-band Hubbard models, starting from a collinear ferromagnetic Hartree-Fock ground state. The results are compared with those of a recently introduced variational…

Strongly Correlated Electrons · Physics 2009-11-07 J. Buenemann , F. Gebhard

Quantum spin Hall insulators, recently realized in HgTe/(Hg,Cd)Te quantum wells, support topologically protected, linearly dispersing edge states with spin-momentum locking. A local magnetic exchange field can open a gap for the edge…

Mesoscale and Nanoscale Physics · Physics 2013-05-30 Carsten Timm

For the Fermi-Hubbard model in the Mott insulator phase, we employ the hierarchy of correlations to study how doublon and holon quasi-particle excitations are affected by adding disorder to the system. We study two types of disorder: charge…

The excitation of high-frequency short-wavelength spin waves is a challenge limiting the application of these propagating magnetization disturbances in information processing systems. We propose a method of local excitation of the…

Mesoscale and Nanoscale Physics · Physics 2021-06-22 Pawel Gruszecki , Igor L. Lyubchanskii , Konstantin Y. Guslienko , Maciej Krawczyk

Spin-flip rates in GaAs quantum dots can be quite slow, thus opening up the possibilities to manipulate spin states in the dots. We present here estimations of inelastic spin-flip rates mediated by hyperfine interaction with nuclei. Under…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Sigurdur I. Erlingsson , Yuli V. Nazarov , Vladimir I. Fal'ko

The spin accumulation in an n-GaAs channel produced by spin extraction into a (Ga,Mn)As contact is measured by cross-sectional imaging of the spin polarization in GaAs. The spin polarization is observed in a 1 \mum thick n-GaAs channel with…

Time-resolved optical measurements of electron-spin dynamics in a (110) GaAs quantum well are used to study the consequences of a strongly anisotropic electron g-tensor, and the origin of previously discovered all-optical nuclear magnetic…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 G. Salis , D. D. Awschalom , Y. Ohno , H. Ohno

A mechanism is proposed to describe the occurrence of distance-dependent dissipation peaks in the dynamics of an atomic force microscope tip oscillating over a surface characterized by a charge density wave state. The dissipation has its…

Mesoscale and Nanoscale Physics · Physics 2016-05-13 Franco Pellegrini

We have studied the edge spin accumulation in a high mobility two-dimensional electron gas formed in a symmetric well with two subbands. This study is strongly motivated by the recent experiment of Hernandez et al. [Phys. Rev. B {\bf 88},…

Mesoscale and Nanoscale Physics · Physics 2018-09-07 Alexander Khaetskii , J. Carlos Egues