Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published May 30, 2004 | Submitted + Published
Journal Article Open

An exact effective two-qubit gate in a chain of three spins

Abstract

We show that an effective two-qubit gate can be obtained from the free evolution of three spins in a chain with nearest neighbor XY coupling, without local manipulations. This gate acts on the two remote spins and leaves the mediating spin unchanged. It can be used to perfectly transfer an arbitrary quantum state from the first spin to the last spin or to simultaneously communicate one classical bit in each direction. One ebit can be generated in half of the time for state transfer. For longer spin chains, we present methods to create or transfer entanglement between the two end spins in half of the time required for quantum state transfer, given tunable coupling strength and local magnetic field. We also examine imperfect state transfer through a homogeneous XY chain.

Additional Information

© 2004 Rinton Press. Received February 6, 2004; Revised May, 3, 2004. Communicated by: I. Cirac & C. Fuchs. We thank Andrew Landahl for help comments on an earlier manuscript. This work is partially supported from the US National Science Foundation under grant no. EIA-0086038. DWL thanks the Richard C. Tolman Endowment Fund at Caltech for partial support. SB thanks for a postdoctoral scholarship at the Caltech Institute for Quantum Information, during which this work started.

Attached Files

Published - YUNqic04.pdf

Submitted - YUNqic04preprint.pdf

Files

YUNqic04preprint.pdf
Files (886.3 kB)
Name Size Download all
md5:acc97450ca84a4a5d3f90fb042274b1c
188.3 kB Preview Download
md5:2481a6a1ea852559eddcf73c6bbb92ec
698.0 kB Preview Download

Additional details

Created:
August 22, 2023
Modified:
October 24, 2023