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Related papers: Tunable All Electric Spin Polarizer

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We report the observation of an anomalous conductance plateau near G = 0.5 G0 (G0 = 2e2/h) in asymmetrically biased AlGaAs/GaAs quantum point contacts (QPCs), with in-plane side gates in the presence of lateral spin-orbit coupling. This is…

Mesoscale and Nanoscale Physics · Physics 2012-04-24 N. Bhandari , P. P. Das , M. Cahay , R. S. Newrock , S. T. Herbert

We propose a novel scheme to efficiently polarize and manipulate the electron spin in a quantum dot. This scheme is based on the spin-orbit interaction and it possesses following advantages: (1) The direction and the strength of the spin…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Qing-feng Sun , X. C. Xie

We report on developing split-gate quantum point contacts (QPCs) that have a tunable length for the transport channel. The QPCs were realized in a GaAs/AlGaAs heterostructure with a two- dimensional electron gas (2DEG) below its surface.…

Mesoscale and Nanoscale Physics · Physics 2013-01-15 M. J. Iqbal , J. P. de. Jong , D. Reuter , A. D. Wieck , C. H. van der Wal

We implement a microscopic spin filter for cold fermionic atoms in a quantum point contact (QPC) and create fully spin-polarized currents while retaining conductance quantization. Key to our scheme is a near-resonant optical tweezer…

We have developed a novel technique for detection of spin polarization with a quantum dot weakly coupled to the objective device. The disturbance to the object in this technique is very small since the detection is performed through…

Mesoscale and Nanoscale Physics · Physics 2016-12-21 Sunwoo Kim , Yoshiaki Hashimoto , Taketomo Nakamura , Shingo Katsumoto

All-electrical control of spin transport in nanostructures has been the central interest and chal- lenge of spin physics and spintronics. Here we demonstrate on-chip spin polarizing/filtering actions by driving the gate-defined one…

Mesoscale and Nanoscale Physics · Physics 2012-11-13 T. -M. Chen , M. Pepper , I. Farrer , G. A. C. Jones , D. A. Ritchie

We theoretically investigate the dynamical nuclear spin polarization in a quantum point contact (QPC) at finite magnetic field. We find that when the QPC is tuned to be spin selective, at the conductance of e^2/h, a finite bias induces a…

Mesoscale and Nanoscale Physics · Physics 2018-03-20 Peter Stano , Tomosuke Aono , Minoru Kawamura

Electron charge transport through a quantum point contact (QPC) driven by an asymmetric spin bias is studied. A large charge current is induced when the transmission coefficient of the QPC jumps from one integer plateau to the next.…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Yanxia Xing , Qing-feng Sun , Jian Wang

The appearance and evolution of an anomalous conductance plateau at 0.4 (in units of 2e2/h) in an In0.52Al0.48As/InAs quantum point contact (QPC), in the presence of lateral spin-orbit coupling, has been studied at T=4.2K as a function of…

Mesoscale and Nanoscale Physics · Physics 2011-07-14 P. P. Das , K. B. Chetry , N. Bhandari , J. Wan , M. Cahay , R. S. Newrock , S. T. Herbert

In this paper, I present a simple method of obtaining spin-polarised current from a QPC with a large Rashba interaction. The origin of this spin polarisation is the adiabatic evolution of spin "up" of the first QPC sub-band, into spin…

Mesoscale and Nanoscale Physics · Physics 2018-11-29 Samuel Bladwell

Nuclear spin polarization is typically generated in GaAs quantum point contacts (QPCs) when an out-of-plane magnetic field gives rise to spin-polarized quantum Hall edge states, and a voltage bias drives transitions between the edge states…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 Y. Ren , W. Yu , S. M. Frolov , J. A. Folk , W. Wegscheider

The observation of a 0.5 conductance plateau in asymmetrically biased quantum point contacts with in-plane side gates has been attributed to the onset of spin-polarized current through these structures. For InAs quantum point contacts with…

Mesoscale and Nanoscale Physics · Physics 2017-04-05 P. P. Das , A. Jones , M. Cahay , S. Kalita , S. S. Mal , N. S. Sterin , T. R. Yadunath , M. Advaitha , S. T. Herbert

Quantum point contact or QPC -- a constriction in a semiconducting two-dimensional (2D) electron system with a quantized conductance -- has been found as the building block of novel spintronic, and topological electronic circuits. They can…

We propose a four-terminal device designed to manipulate by all electrical means the spin of a magnetic adatom positioned at the edge of a quantum spin Hall insulator. We show that an electrical gate, able to tune the interface resistance…

Mesoscale and Nanoscale Physics · Physics 2013-12-02 Awadhesh Narayan , Aaron Hurley , Stefano Sanvito

Tunable couplers are a key building block of superconducting quantum processors, enabling high on-off ratios for two-qubit entangling interactions. While qubit-qubit interaction can be turned off, residual wavefunctions delocalize…

Quantum Physics · Physics 2026-02-23 Zhongyi Jiang , Simon Geisert , Sören Ihssen , Ioan M. Pop , Mohammad H. Ansari

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 study ballistic transport through semiconductor quantum point contact systems under different confinement geometries and applied fields. In particular, we investigate how the {\em lateral} spin-orbit coupling, introduced by asymmetric…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Anh T. Ngo , P. Debray , Sergio Ulloa

We propose two new approaches for regulating spin polarization and spin inversion in a conducting junction within a tight-binding framework based on wave-guide theory. The system comprises a magnetic quantum ring with finite modulation in…

Mesoscale and Nanoscale Physics · Physics 2018-09-19 Moumita Patra , Santanu K. Maiti

We demonstrate the use of optimal control to design two entropy-manipulating quantum gates which are more complex than the corresponding, commonly used, gates, such as CNOT and Toffoli (CCNOT): A 2-qubit gate called PE (polarization…

Quantum Physics · Physics 2014-11-19 Yosi Atia , Yuval Elias , Tal Mor , Yossi Weinstein

We use spatial spin separation by a magnetic focusing technique to probe the polarization of quantum point contacts. The point contacts are fabricated from p-type GaAs/AlGaAs heterostructures. A finite polarization is measured in the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 L. P. Rokhinson , L. N. Pfeiffer , K. W. West
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