Robust Stability of Uncertain Quantum Systems
  This paper considers the problem of robust stability for a class of uncertain quantum systems subject to unknown perturbations in the system Hamiltonian. Some general stability results are given for different classes of perturbations to the system Hamiltonian. Then, the special case of a nominal linear quantum system is considered with either quadratic or non-quadratic perturbations to the system Hamiltonian. In this case, robust stability conditions are given in terms of strict bounded real conditions. 
Ian R. Petersen, Valery Ugrinovskii and Matthew R. James
quant-ph cs.SY math.OC