Collapse and Revival and Cat States with an N Spin System

TL;DR

This paper explores collapse and revival phenomena in a qubit-big spin system, demonstrating the creation of Schrödinger cat states with potential for quantum metrology, especially approaching the Heisenberg limit.

Contribution

It introduces a regime of collapse and revival dynamics in a qubit and big spin system using spin coherent states, enabling generation of highly sensitive quantum states.

Findings

Demonstrates collapse and revival in a qubit-big spin system.

Shows creation of Schrödinger cat states from these dynamics.

States have potential for quantum metrology near the Heisenberg limit.

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 behaviour 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 "Schrodinger 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.