Universal quantum computation in a semiconductor quantum wire network

Journal Article · Mon Nov 15 04:00:00 EST 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.82.052322· OSTI ID:21528601

Sau, Jay D; Das Sarma, S ^[1]; Tewari, Sumanta ^[1]

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1. Condensed Matter Theory Center and Joint Quantum Institute, Department of Physics, University of Maryland, College Park, Maryland 20742-4111 (United States)

Universal quantum computation (UQC) using Majorana fermions on a two-dimensional topological superconducting (TS) medium remains an outstanding open problem. This is because the quantum gate set that can be generated by braiding of the Majorana fermions does not include any two-qubit gate and also no single-qubit {pi}/8 phase gate. In principle, it is possible to create these crucial extra gates using quantum interference of Majorana fermion currents. However, it is not clear if the motion of the various order parameter defects (vortices, domain walls, etc.), to which the Majorana fermions are bound in a TS medium, can be quantum coherent. We show that these obstacles can be overcome using a semiconductor quantum wire network in the vicinity of an s-wave superconductor, by constructing topologically protected two-qubit gates and any arbitrary single-qubit phase gate in a topologically unprotected manner, which can be error corrected using magic-state distillation. Thus our strategy, using a judicious combination of topologically protected and unprotected gate operations, realizes UQC on a quantum wire network with a remarkably high error threshold of 0.14 as compared to 10{sup -3} to 10{sup -4} in ordinary unprotected quantum computation.

• OSTI ID: 21528601
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 5 Vol. 82; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COMPUTERS
DIMENSIONLESS NUMBERS
FERMIONS
MATERIALS
MATHEMATICS
NANOSTRUCTURES
ORDER PARAMETERS
PARTIAL WAVES
QUANTUM COMPUTERS
QUANTUM WIRES
S WAVES
SEMICONDUCTOR MATERIALS
TOPOLOGY
TWO-DIMENSIONAL CALCULATIONS
VORTICES