Detailed Calculation of the Average Work Done in a Ground State Quench of the Quantum Ising Model

  • Salvador T. Laurente Jr. University of the Philippines Diliman
  • Francis N.C. Paraan University of the Philippines Diliman


A detailed derivation of the exact expression for the average work done
in a transverse f ield quench of the quantum Ising model ground state
is presented. In the thermodynamic limit, it is proved that the average
work done generally has inflection points at the critical field for the
pre-quench quantum phase transition. The first divergent field derivative
is calculated and is shown to diverge logarithmically. We also
demonstrate that the average work done is equal to the product of the
transverse magnetization of the pre-quench ground state and the change
in the magnetic f ield.

Keywords: Quantum quench, quantum Ising model, quantum phase