A quantum phase transition in a quantum external field: Superposing two magnetic phases

作者：Rams Marek M; Zwolak Michael; Damski Bogdan^*

来源：Scientific Reports, 2012, 2: 655.

DOI：10.1038/srep00655

We study an Ising chain undergoing a quantum phase transition in a quantum magnetic field. Such a field can be emulated by coupling the chain to a central spin initially in a superposition state. We show that - by adiabatically driving such a system - one can prepare a quantum superposition of any two ground states of the Ising chain. In particular, one can end up with the Ising chain in a superposition of ferromagnetic and paramagnetic phases - a scenario with no analogue in prior studies of quantum phase transitions. %26lt;br%26gt;Remarkably, the resulting magnetization of the chain encodes the position of the critical point and universal critical exponents, as well as the ground state fidelity.

• 出版日期2012-9-13