Observing a quantum phase transition by measuring a single spin
1 Physikalisches Institut, Albert- Ludwigs-Universität Freiburg - Hermann-Herder-Straße 3, 79104 Freiburg, Germany
2 Department of Physics, University of California - Berkeley, CA 94720, USA
Received: 12 May 2014
Accepted: 25 July 2014
We show that the ground-state quantum correlations of an Ising model can be detected by monitoring the time evolution of a single spin alone, and that the critical point of a quantum phase transition is detected through a maximum of a suitably defined observable. A proposed implementation with trapped ions realizes an experimental probe of quantum phase transitions which is based on quantum correlations and scalable for large system sizes.
PACS: 03.67.Ac – Quantum algorithms, protocols, and simulations / 05.30.Rt – Quantum phase transitions / 37.10.Ty – Ion trapping
© EPLA, 2014