THE BEHAVIOR, OF INDIVIDUAL ULTRA-SMALL CAPACITANCE QUANTUM DEVICES

We apply quantum state diffusion, theory to an open angular system, su ch as a quantum capacitor or rotor. We consider various physically int eresting Hamiltonian and environment terms, such as those which give r ise to tunnelling, and dissipation. Quantum state diffusion (QSD) mode ls tile irreversible behaviour of an individual open system, underpinn ed by the statistics corresponding to a Bloch type of master equation evolution. Our work therefore provides, examples of individual quantum device behaviour for cases where the ensemble evolution is Markovian. Since the Markovian approximation is decent for many experiments and since quantum device experiments usually address just one device, QSD should prove to be a useful tool for future device research.