Long-lived qubit from three spin-(1/2) atoms

Journal Article · Fri Jul 15 04:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.84.012322· OSTI ID:22038628

Rui, Han ^[1]; Loerch, Niels ^[1]; Suzuki, Jun ^[2]; Englert, Berthold-Georg ^[1]

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1. Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore)
2. National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda ku, Tokyo 101-8430 (Japan)

A system of three spin-(1/2) atoms allows the construction of a reference-frame-free (RFF) qubit in the subspace with total angular momentum j=1/2. The RFF qubit stays coherent perfectly as long as the spins of the three atoms are affected homogeneously. The inhomogeneous evolution of the atoms causes decoherence, but this decoherence can be suppressed efficiently by applying a bias magnetic field of modest strength perpendicular to the plane of the atoms. The resulting lifetime of the RFF qubit can be many days, making RFF qubits of this kind promising candidates for quantum information storage units. Specifically, we examine the situation of three {sup 6}Li atoms trapped in a CO{sub 2}-laser-generated optical lattice and find that, with conservatively estimated parameters, a stored qubit maintains a fidelity of 0.9999 for two hours.

• OSTI ID: 22038628
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 1 Vol. 84; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
CARBON DIOXIDE LASERS
FERMIONS
LITHIUM 6
QUBITS
SPIN
TRAPPING