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Pauli spin blockade in quantum dot systems occurs when the charge transport is allowed only for some spin states, and it has been an efficient tool in spin-based qubit devices in semiconductors. We theoretically investigate a Pauli spin…

Mesoscale and Nanoscale Physics · Physics 2022-08-24 Yun-Pil Shim

The hyperpolarisation of nuclear spins within target molecules is a critical and complex challenge in magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) spectroscopy. Hyperpolarisation offers enormous gains in signal and…

The process $e^+e^- \rightarrow N\bar N$ is studied nearby a threshold with account for polarizations of all initial and final particles. The nucleon polarization $\bm \zeta^N$ reveals a strong energy dependence due to that of the nucleon…

High Energy Physics - Phenomenology · Physics 2011-05-26 A. E. Bondar , V. F. Dmitriev , A. I. Milstein , V. M. Strakhovenko

We theoretically investigate polarization-entangled photon generation by using a semiconductor quantum dot embedded in a microcavity. The entangled states can be produced by the application of two cross-circularly polarized laser fields.…

We study the absorption and emission polarization of single semiconductor quantum dots in semiconductor nanowires. We show that the polarization of light absorbed or emitted by a nanowire quantum dot strongly depends on the orientation of…

We report on the dynamic nuclear polarization of a single charge-tunable self-assembled InAs/GaAs quantum dot in a longitudinal magnetic field of $\sim$0.2T. The hyperfine interaction between the optically oriented electron and nuclei spins…

We show that a quantum wire device with spin splitting can work as an active spin polarizer. Hot electrons in one `spin' subband (e.g. `spin-up') may pass such a device with weak electron pair scattering, while electrons in the opposite…

Condensed Matter · Physics 2009-10-22 Gerhard Fasol , Hiroyuki Sakaki

For the model Hamiltonian describing the electron-nuclear dynamics of a quantum dot, we obtained an exact expression for the limiting nuclear polarization as a function of the number of groups of equivalent nuclei. It is shown that the…

Mesoscale and Nanoscale Physics · Physics 2008-01-10 G. G. Kozlov

This paper has been updated by the author to: arXiv:1012.0060v1 [cond-mat.mes-hall], titled "Collective Nuclear Stabilization by Optically Excited Hole in Quantum Dot"

Mesoscale and Nanoscale Physics · Physics 2011-02-01 Wen Yang , L. J. Sham

The concept of nuclear spin temperature has been a cornerstone of the theory of dynamic nuclear spin polarization by electrons in various semiconductor structures for decades. Still, it is not always applicable to strongly localized…

Mesoscale and Nanoscale Physics · Physics 2024-08-13 D. S. Smirnov , K. V. Kavokin

We theoretically investigate the spin dynamics of a heavy hole confined to an unstrained III-V semiconductor quantum dot and interacting with a narrowed nuclear-spin bath. We show that band hybridization leads to an exponential decay of…

Mesoscale and Nanoscale Physics · Physics 2010-12-27 Jan Fischer , Daniel Loss

We discuss various methods of all-optical spin control in semiconductor quantum dots. We present different ways of rotating a single confined electron spin by optical coupling to a trion state. We also discuss a method for controlling the…

Mesoscale and Nanoscale Physics · Physics 2013-01-17 Pawel Machnikowski , Anna Grodecka , Carsten Weber , Andreas Knorr

It is shown that, for appropriate values of electron energy, the silicene dot can work as a controllable spin polarizer. The spin polarizer can polarize the spin of transmitted electrons from nearly pure down to nearly pure up by changing…

Mesoscale and Nanoscale Physics · Physics 2015-01-19 Hamidreza Simchi , Mahdi Esmaeilzadeh , Hossein Mazidabadi , Mohammad Norouzi

Semiconductor point contacts can be a useful tool for producing spin-polarized currents in the presence of spin-orbit (SO) interaction. Neither magnetic fields nor magnetic materials are required. By numerical studies, we show that (i) the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Mikio Eto , Tetsuya Hayashi , Yuji Kurotani

We demonstrate a coherent quantum measurement for the determination of the degree of polarization (DOP). This method allows to measure the DOP in the presence of fast polarization state fluctuations, difficult to achieve with the typically…

Quantum Physics · Physics 2009-11-10 M. Legre , M. Wegmuller , N. Gisin

We formulate a model of a semiconductor Quantum Dot laser with injection of spin-polarized electrons. As compared to higher-dimensionality structures, the Quantum-Dot-based active region is known to improve laser properties, including the…

Mesoscale and Nanoscale Physics · Physics 2010-09-03 Rafał Oszwałdowski , Christian Gøthgen , Igor Žutić

We proposed and demonstrated that the nuclear spins of the host lattice in GaAs double quantum dots can be strongly polarized in either of two opposite directions, parallel or antiparallel to an external magnetic field. The direction is…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Ryo Takahashi , Kimitoshi Kono , Seigo Tarucha , Keiji Ono

The ground state of an acceptor-bound hole in a zinc-blende semiconductor is formed by four eigenstates of the total angular momentum, which is a vector sum of spin and orbital moment of the hole. As a result, the hyperfine interaction of…

Mesoscale and Nanoscale Physics · Physics 2015-06-16 K. V. Kavokin , A. V. Koudinov

We use the spin-polarized excitons in a single quantum dot to design optical controls for basic operations in quantum computing. We examine the ultrafast nonlinear optical processes required and use the coherent nonlinear optical responses…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Pochung Chen , C. Piermarocchi , L. J. Sham

We present a technique for manipulating the nuclear spins and the emission polarization from a single optically active quantum dot. When the quantum dot is tunnel coupled to a Fermi sea, we have discovered a natural cycle in which an…

Mesoscale and Nanoscale Physics · Physics 2015-03-17 C. Kloeffel , P. A. Dalgarno , B. Urbaszek , B. D. Gerardot , D. Brunner , P. M. Petroff , D. Loss , R. J. Warburton
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