Departments of Mathematics and Physics
PhD Harvard University, 1984
Professor King’s main area of research is quantum information theory. Research in this field centers around the question of how the unique properties of quantum systems (such as state superpositions and entanglement) can be exploited to enhance the efficiency of tasks involving information storage and transfer. Well known examples of this quantum advantage include secure communication over a public channel, violation of Bell’s inequalities, and Shor’s quantum factoring algorithm. Professor King has studied problems in this arena related to computation and communication (channel capacity, data compression), mathematics (completely positive maps, operator spaces) and nano physics (energy transfer and dynamics). In particular he has proved that several types of noisy quantum channels exhibit an additivity property that allows their channel capacities to be efficiently computed. Professor King also conducts research in pure mathematics (matrix analysis) and classical dynamical systems (stability of switching systems).
1. C. King, B. Barbiellini, D. Moser, V. Renugopalakrishnan, “Exactly soluble model of resonant energy transfer between molecules”, Phys. Rev. B 85, 125106 (2012).
2. C. King and D. Moser, “Average output entropy for quantum channels”, J. Math. Phys. vol. 52, 112202 (2011); selected for the November 2011 issue of Virtual Journal of Quantum Information.
3. C. King, “Conditions for quadratic stability of a multi-parameter switching system”, Journal of Nonlinear Systems and Applications, vol. 2, 26 — 34 (2011).
4. M. Fukuda and C. King, “Entanglement of random subspaces via the Hastings bound”, J. Math. Phys vol. 51, 042201 (2010).
5. M. Fukuda, C. King and D. Moser, “Comments on Hastings’ Additivity Counterexamples”, Commun. Math. Phys., vol. 296, no. 1, 111 (2010).