Abstract:

We are interested in fundamental limits to computation imposed by physical constraints. In particular, the physical laws of motion constrain the speed at which a computer can transition between well-defined states. Certain time bounds are known, but these are not tight bounds. For computation, we also need to consider bounds in the presence of control functions. Here, we use a numerical search approach to discover specific optimal control schemes. We present results for two coupled spins controlled in two scenarios: (i) a single control field influencing each spin separately; (ii) two orthogonal control fields influencing each spin.

@inproceedings(SS-UCNC13-num,
  author = "Benjamin Russell and Susan Stepney",
  title = "Numerical Analysis of Quantum Speed Limits:
                controlled quantum spin chain systems with constrained control functions",
  pages = "209-219",             
  crossref = "UCNC13"
)

@proceedings(UCNC13,
  title = "Unconventional Computation and Natural Computation 2013, Milan, Italy, July 2013",
  booktitle = "Unconventional Computation and Natural Computation 2013, Milan, Italy, July 2013",
  series = "LNCS",
  volume = 7956,
  publisher = "Springer",
  year = 2013
)