Heisenberg-Limited Atom Clocks Based on Entangled Qubits

TY - JOUR

T1 - Heisenberg-Limited Atom Clocks Based on Entangled Qubits

AU - Kessler, E.M.

AU - Kómár, P.

AU - Bishof, M.

AU - Jiang, L.

AU - Sørensen, Anders Søndberg

AU - Ye, J.

AU - Lukin, M.D.

PY - 2014/5/15

Y1 - 2014/5/15

N2 - We present a quantum-enhanced atomic clock protocol based on groups of sequentially larger Greenberger-Horne-Zeilinger (GHZ) states that achieves the best clock stability allowed by quantum theory up to a logarithmic correction. Importantly the protocol is designed to work under realistic conditions where the drift of the phase of the laser interrogating the atoms is the main source of decoherence. The simultaneous interrogation of the laser phase with a cascade of GHZ states realizes an incoherent version of the phase estimation algorithm that enables Heisenberg-limited operation while extending the coherent interrogation time beyond the laser noise limit. We compare and merge the new protocol with existing state of the art interrogation schemes, and identify the precise conditions under which entanglement provides an advantage for clock stabilization: it allows a significant gain in the stability for short averaging time.

AB - We present a quantum-enhanced atomic clock protocol based on groups of sequentially larger Greenberger-Horne-Zeilinger (GHZ) states that achieves the best clock stability allowed by quantum theory up to a logarithmic correction. Importantly the protocol is designed to work under realistic conditions where the drift of the phase of the laser interrogating the atoms is the main source of decoherence. The simultaneous interrogation of the laser phase with a cascade of GHZ states realizes an incoherent version of the phase estimation algorithm that enables Heisenberg-limited operation while extending the coherent interrogation time beyond the laser noise limit. We compare and merge the new protocol with existing state of the art interrogation schemes, and identify the precise conditions under which entanglement provides an advantage for clock stabilization: it allows a significant gain in the stability for short averaging time.

U2 - 10.1103/PhysRevLett.112.190403

DO - 10.1103/PhysRevLett.112.190403

M3 - Journal article

C2 - 24877919

SN - 0031-9007

VL - 112

JO - Physical Review Letters

JF - Physical Review Letters

IS - 19

M1 - 190403

ER -