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Related papers: Universal Quantum Computing with Spin and Valley

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At the center of quantum computing1 realization is the physical implementation of qubits - two-state quantum information units. The rise of graphene2 has opened a new door to the implementation. Because graphene electrons simulate…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 G. Y. Wu , N. -Y. Lue , L. Chang

Experimental implementations of quantum computer architectures are now being investigated in many different physical settings. The full set of requirements that must be met to make quantum computing a reality in the laboratory [1] is…

Quantum Physics · Physics 2009-11-06 D. P. DiVincenzo , D. Bacon , J. Kempe , G. Burkard , K. B. Whaley

We show how to construct a universal set of quantum logic gates using control over exchange interactions and single- and two-spin measurements only. Single-spin unitary operations are teleported instead of being executed directly, thus…

Quantum Physics · Physics 2016-09-08 L. -A. Wu , D. A. Lidar

Quantum computation requires many qubits that can be coherently controlled and coupled to each other. Qubits that are defined using lithographic techniques are often argued to be promising platforms for scalability, since they can be…

Mesoscale and Nanoscale Physics · Physics 2020-04-27 L. Petit , H. G. J. Eenink , M. Russ , W. I. L. Lawrie , N. W. Hendrickx , J. S. Clarke , L. M. K. Vandersypen , M. Veldhorst

The universal quantum computation is obtained when there exists asymmetric anisotropic exchange between electron spins in coupled semiconductor quantum dots. The asymmetric Heisenberg model can be transformed into the isotropic model…

Quantum Physics · Physics 2009-11-13 Xiang Hao , Shiqun Zhu

We theoretically propose a set of universal quantum gates acting on a hybrid qubit formed by coupling a quantum dot spin qubit and Majorana fermion qubit. First, we consider a quantum dot tunnel-coupled to two topological superconductors.…

Mesoscale and Nanoscale Physics · Physics 2016-08-03 Silas Hoffman , Constantin Schrade , Jelena Klinovaja , Daniel Loss

Quantum computation in solid state quantum dots faces two significant challenges: Decoherence from interactions with the environment and the difficulty of generating local magnetic fields for the single qubit rotations. This paper presents…

Quantum Physics · Physics 2007-05-23 C. Stephen Hellberg

Quantum processors which combine the long decoherence times of spin qubits together with fast optical manipulation of excitons have recently been the subject of several proposals. I show here that arbitrary single- and entangling two-qubit…

Quantum Physics · Physics 2007-05-23 Brendon W. Lovett

We devise a platform for noise-resistant quantum computing using the valley degree of freedom of Si quantum dots. The qubit is encoded in two polarized (1,1) spin-triplet states with different valley compositions in a double quantum dot,…

Mesoscale and Nanoscale Physics · Physics 2015-05-28 Dimitrie Culcer , A. L. Saraiva , Belita Koiller , Xuedong Hu , S. Das Sarma

Current semiconductor qubits rely either on the spin or on the charge degree of freedom to encode quantum information. By contrast, in bilayer graphene the valley degree of freedom, stemming from the crystal lattice symmetry, is a robust…

The author analyzes quantum computation with the hybrid qubit (HQ) that is encoded using the three-electron configuration of a double quantum dot. All gate operations are controlled with electric signals, while the qubit remains at an…

Mesoscale and Nanoscale Physics · Physics 2015-07-14 Sebastian Mehl

We propose a method for implementation of an universal set of one- and two-quantum-bit gates for quantum computation in the system of two coupled electrons with constant non-diagonal exchange interaction. Suppression of the exchange…

Mesoscale and Nanoscale Physics · Physics 2015-06-23 A. V. Nenashev , A. F. Zinovieva , A. V. Dvurechenskii , A. Yu. Gornov , T. S. Zarodnyuk

Exchange-coupled singlet-triplet spin qubits in two gate-defined double quantum dots are considered theoretically. Using charge density operators to describe the double-dot orbital states, we calculate the Coulomb couplings between the…

Mesoscale and Nanoscale Physics · Physics 2015-05-28 Guy Ramon

We propose to implement quantum computing based on electronic spin qubits by controlling the propagation of the electron wave packets through the helical edge states of quantum spin Hall systems (QSHs). Specfically, two non-commutative…

Mesoscale and Nanoscale Physics · Physics 2014-04-04 Wei Chen , Zheng-Yuan Xue , Z. D. Wang , R. Shen , D. Y. Xing

We prove that universal quantum computation is possible using only (i) the physically natural measurement on two qubits which distinguishes the singlet from the triplet subspace, and (ii) qubits prepared in almost any three different…

Quantum Physics · Physics 2009-11-11 Terry Rudolph , Shashank Soyuz Virmani

Electrons confined in silicon quantum dots exhibit orbital, spin, and valley degrees of freedom. The valley degree of freedom originates from the bulk bandstructure of silicon, which has six degenerate electronic minima. The degeneracy can…

Mesoscale and Nanoscale Physics · Physics 2021-05-05 F. Borjans , X. Zhang , X. Mi , G. Cheng , N. Yao , C. A. C. Jackson , L. F. Edge , J. R. Petta

We propose an all optical quantum computation scheme, with trapped electron spin qubits, using their Coulomb exchange interaction with optically excited microcavity exciton-polaritons. This paper describes a single qubit rotation, which…

Quantum Physics · Physics 2012-08-13 Shruti Puri , Na Young Kim , Eisuke Abe , Yoshihisa Yamamoto

With silicon being the go-to material for spin qubits, and motivated by the demand of a scalable quantum computer architecture for fast and reliable quantum information transfer on-chip, we study coherent electron transport in a silicon…

Mesoscale and Nanoscale Physics · Physics 2019-08-02 Xinyu Zhao , Xuedong Hu

The presence of degenerate conduction band valleys and how they are mixed by interfaces play critical roles in determining electron interaction and spectrum in a silicon nanostructure. Here we investigate how the valley phases affect the…

Mesoscale and Nanoscale Physics · Physics 2021-07-05 Bilal Tariq , Xuedong Hu