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arXiv:1302.2806 · Physical Review A

Collapse and revival and cat states with an N -spin system

Shane Dooley, Francis McCrossan, Derek Harland, M. J. Everitt, Timothy P. Spiller

Published May 24, 2013• 34 citations
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Abstract

We discuss collapse and revival of Rabi oscillations in a system comprising a qubit and a ``big spin'' (made of $N$ qubits, or spin-$1/2$ particles). We demonstrate a regime of behavior analogous to conventional collapse and revival for a qubit-field system, employing spin coherent states for the initial state of the big spin. These dynamics can be used to create a cat state of the big spin. Even for relatively small values of $N$, states with significant potential for quantum metrology applications can result, giving sensitivity approaching the Heisenberg limit.

DOI
10.1103/physreva.87.052323

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We study the dynamics of the Jaynes-Cummings Model for an array of NqN_qNq​ two level systems (or qubits) interacting with a quantized single mode electromagnetic cavity (or quantum bus). For an initial cavity coherent state ∣α>| α>∣α> and the qubit system in a specified `basin of attraction' in its Hilbert space, we demonstrate the oscillation of a superposition of two macroscopic quantum states between the qubit system and the field mode. From the perspective of either the qubit or the field system, there is collapse and revival of a `Schrödinger Cat' state.
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We study the dynamics of the Jaynes-Cummings Model for an array of NqN_qNq​ two level systems (or qubits) interacting with a quantized single mode electromagnetic cavity (or quantum bus). For an initial cavity coherent state ∣α>| \alpha >∣α> and the qubit system in a specified `basin of attraction' in its Hilbert space, we demonstrate the oscillation of a superposition of two macroscopic quantum states between the qubit system and the field mode. From the perspective of either the qubit or the field system, there is collapse and revival of a `Schr\odinger Cat' state.
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