Some implications of superconducting quantum interference to the application of master equations in engineering quantum technologies

  1. S.N.A. Duffus,
  2. K.N. Bjergstrøm,
  3. V.M. Dwyer,
  4. J.H. Samson,
  5. T.P. Spiller,
  6. W. J. Munro,
  7. Kae Nemoto,
  8. and M. J. Everitt
In this paper we consider the modelling and simulation of open quantum systems from a device engineering perspective. We derive master equations at different levels of approximation
for a Superconducting Quantum Interference Device (SQUID) ring coupled to an ohmic bath and demonstrate that the different levels of approximation produce qualitatively different dynamics. We discuss the issues raised when seeking to obtain Lindbladian dissipation and show, in this case, that the external flux (which may be considered to be a control variable in some applications) is not confined to the Hamiltonian, as often assumed in quantum control, but also appears in the Lindblad terms.