English
Related papers

Related papers: Bias-controllable intrinsic spin polarization in a…

200 papers

An alternating electric field, applied to a quantum dot, couples to the electron spin via the spin-orbit interaction. We analyze different types of spin-orbit coupling known in the literature and find two efficient mechanisms of spin…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Vitaly N. Golovach , Massoud Borhani , Daniel Loss

We propose realistic methods to detect local spin polarization, which utilize a quantum dot side coupled to the target system. By choosing appropriate states in the dot, we can put spin selectivity to the dot and detect spins in the target…

Mesoscale and Nanoscale Physics · Physics 2011-06-14 Tomohiro Otsuka , Eisuke Abe , Yasuhiro Iye , Shingo Katsumoto

We have studied theoretically the possibility of ultra-fast manipulation of a single electron spin in 2D semiconductor quantum dots, by means of high-frequency time-dependent electric fields. The electron spin degree of freedom is excited…

Mesoscale and Nanoscale Physics · Physics 2014-10-24 J. A. Budagosky , A. Castro

We present a set of concrete and realistic ideas for the implementation of a small-scale quantum computer using electron spins in lateral GaAs/AlGaAs quantum dots. Initialization is based on leads in the quantum Hall regime with tunable…

We present an approach for entangling electron spin qubits localized on spatially separated impurity atoms or quantum dots via a multi-electron, two-level quantum dot. The effective exchange interaction mediated by the dot can be understood…

Mesoscale and Nanoscale Physics · Physics 2015-06-10 V. Srinivasa , H. Xu , J. M. Taylor

We propose a method to electrically control electron spins in donor-based qubits in silicon. By taking advantage of the hyperfine coupling difference between a single-donor and a two-donor quantum dot, spin rotation can be driven by…

Mesoscale and Nanoscale Physics · Physics 2017-03-17 Yu Wang , Chin-Yi Chen , Gerhard Klimeck , Michelle Y. Simmons , Rajib Rahman

The spin-orbit coupling influences the total spin of semiconductor quantum dots. We analyze the theoretical prediction for the combined effects of spin-orbit coupling, weak vertical magnetic fields and deformation of the dot. Our results…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Manuel Valin-Rodriguez , Antonio Puente , Llorens Serra , Enrico Lipparini

A crucial requirement for quantum information processing is the realization of multiple-qubit quantum gates. Here, we demonstrate an electron spin based all-electrical two-qubit gate consisting of single spin rotations and inter-dot spin…

Quantum Physics · Physics 2015-05-30 R. Brunner , Y. -S. Shin , T. Obata , M. Pioro-Ladrière , T. Kubo , K. Yoshida , T. Taniyama , Y. Tokura , S. Tarucha

We propose a new device to create a tunable all-electric spin polarizer: a quantum point contact (QPC) with four gates -- two in-plane side gates in series. The first pair of gates, near the source, is asymmetrically biased to create spin…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 J. Charles , N. Bhandari , J. Wan , M. Cahay , R. S. Newrock

We demonstrate bias control of the hyperfine coupling between a single electron in an InAs quantum dot and the surrounding nuclear spins monitored through the positively charged exciton X+ emission. In applied longitudinal magnetic fields…

Mesoscale and Nanoscale Physics · Physics 2013-08-19 J. Nilsson , L. Bouet , A. J. Bennett , T. Amand , R. M. Stevenson , I. Farrer , D. A. Ritchie , S. Kunz , X. Marie , A. J. Shields , B. Urbaszek

We propose a quantum processor based upon single-molecule magnets and spin transfer torque described by PT-symmetric quantum mechanics. In recent years PT-symmetric Hamiltonians have been used to obtain stability thresholds of various…

Mesoscale and Nanoscale Physics · Physics 2019-05-22 Aleix Bou Comas , Eugene M. Chudnovsky , Javier Tejada

Focusing on the efficient probe and manipulation of single-particle spin states, we investigate the coupled spin and orbital dynamics of a spin 1/2 particle in a harmonic potential subject to ultrastrong spin-orbit interaction and external…

Mesoscale and Nanoscale Physics · Physics 2014-01-21 C. Echeverria-Arrondo , E. Ya. Sherman

A new way of getting controlled spin dependent transport through a two-terminal bridge setup is explored. The system comprises a magnetic quantum ring which is directly coupled to a magnetic quantum wire and subjected to an in-plane…

Mesoscale and Nanoscale Physics · Physics 2015-07-09 Santanu K. Maiti

We report electronic control and measurement of an imbalance between spin-up and spin-down electrons in micron-scale open quantum dots. Spin injection and detection was achieved with quantum point contacts tuned to have spin-selective…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 E. J. Koop , B. J. van Wees , D. Reuter , A. D. Wieck , C. H. van der Wal

We consider the full driven quantum dynamics of a qubit realized as spin of electron in a one-dimensional double quantum dot with spin-orbit coupling. The driving perturbation is taken in the form of a single half-period pulse of electric…

Mesoscale and Nanoscale Physics · Physics 2010-09-28 D. V. Khomitsky , E. Ya. Sherman

We suggest a new spin orientation mechanism for localized electrons: $dynamic~electron~spin~polarization~provided~by~nuclear~spin~fluctuations$. The angular momentum for the electrons is gained from the nuclear spin system via the hyperfine…

Mesoscale and Nanoscale Physics · Physics 2020-10-14 D. S. Smirnov , T. S. Shamirzaev , D. R. Yakovlev , M. Bayer

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

Achieving control over the electron spin in quantum dots (artificial atoms) or real atoms promises access to new technologies in conventional and in quantum information processing. Here we review our proposal for quantum computing with…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Vitaly N. Golovach , Daniel Loss

Single particle interference lies at the heart of quantum mechanics. The archetypal double-slit experiment has been repeated with electrons in vacuum up to the more massive $C_{60}$ molecules. Mesoscopic rings threaded by a magnetic flux…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Andrea Donarini , Georg Begemann , Milena Grifoni

A scheme for a spin polarization direction switch is investigated by studying the spin-dependent electron transport of an asymmetrical quantum wire (QW) with Rashba spin-orbit coupling (SOC). It is found that the magnitude of the…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 Zhonghui Xu , Xianbo Xiao , Yuguang Chen