Exchange gate in solid-state spin-quantum computation: The applicability of the Heisenberg model

2004/10/31 by V. W. Scarola, S. Das Sarma
Computer Science · Physics and Astronomy · #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum and electron transport phenomena #cond-mat.mes-hall #quant-ph

paper · pdf · doi:10.1103/physreva.71.032340

published as Phys. Rev. A 71, 032340 (2005) · 13 pages, 8 figures

openalex publication_date 2005/03/24 · arxiv created 2005/09/14 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

Solid-state quantum-computing proposals rely on adiabatic operations of the exchange gate among localized spins in nanostructures. We study corrections to the Heisenberg interaction between lateral semiconductor quantum dots in an external magnetic field. Using exact diagonalization we obtain the regime of validity of the adiabatic approximation. We also find qualitative corrections to the Heisenberg model at high magnetic fields and in looped arrays of spins. Looped geometries of localized spins generate flux-dependent multispin terms which go beyond the basic Heisenberg model.

Citations

• The Diamagnetism of the Free Electron
• Quantal phase factors accompanying adiabatic changes
• Single-shot read-out of an individual electron spin in a quantum dot

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• Recipes for spin-based quantum computing
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