Switching global correlations on and off in a many-body quantum state by tuning local entanglement.

Abstract

A quantum many-body state built on a classical 1D Ising model with locally entangled qubits is considered. This setup can model an infinite player quantum Prisoner's dilemma game with each site representing two entangled players (or qubits). The local entanglement γ between two qubits placed on a site in the 1D Ising model and classical coupling between adjacent sites of the Ising model have an apposite influence on qubits. It points to a counter-intuitive situation wherein local entanglement at a site can exactly cancel global correlations, signaling an artificial quantum many-body state wherein, by locally tuning the entanglement at a particular site, one can transition from a strongly correlated quantum state to an uncorrelated quantum state and then to a correlated classical state. In other words, we can simulate a state similar to a type II superconducting state via local tuning of entanglement in a 1D Ising chain with entangled qubits.