Electron dynamics in quantum gate operation

We model the evolving time- dependent electronic structure of a solid- state quantum gate as it performs basic quantum operations. Our time- dependent configuration- interaction method follows the evolution of two donor electron spin qubits interacting with a third, optically excited, control spin i...

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Bibliographic Details
Main Authors: Kerridge, A, Harker, AH, Stoneham, AM
Format: Article in Journal/Newspaper
Language:English
Published: IOP PUBLISHING LTD 2007
Subjects:
Online Access:https://discovery.ucl.ac.uk/id/eprint/162656/1/0953-8984_19_28_282201.pdf
https://discovery.ucl.ac.uk/id/eprint/162656/
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Summary:We model the evolving time- dependent electronic structure of a solid- state quantum gate as it performs basic quantum operations. Our time- dependent configuration- interaction method follows the evolution of two donor electron spin qubits interacting with a third, optically excited, control spin in an applied magnetic field, a possible realization of the basic component of a proposed quantum information processor. We identify unitary operations which approximately disentangle the control spin, and use them to construct high-accuracy two- electron operations that are locally equivalent to CNOT, SWAP and root SWAP operations. From our evaluation of the accuracy of a set of candidate gates we estimate the residual entanglement of the control electron and overall gate operation times. These results attest to the feasibility of the silicon- based quantum gates proposed by Stoneham, Fisher and Greenland.