A reminder of Adrian Hutter's talk today at 4pm in the Time room.
Title: A Quantum Information Approach to Statistical Physics
Abstract: I will first present a theorem based on the
Decoupling Theorem of [1] which gives sufficient and necessary
conditions for a quantum channel (CPTPM) being such that it yields
the same output for almost all possible inputs. This theorem allows
us to reproduce and generalize results of [2,3], in which
cornerstones of statistical physics are derived from first
principles of quantum mechanics, in a very natural and easy way.
Specifically, we express them in a way which allows to apply results
about random 2-qubit interactions [4]. Furthermore, we apply this
theorem to provide a criterion for whether different initial states
of some subspace of a quantum mechanical system in contact with an
environment have at some given time already evolved to the same
state or not. As it turns out, this question can be answered by
examining a simple entropic inequality evaluated for just one
particular state [5]. Applying this criterion to realistic
Hamiltonians with local interactions may lead to improved bounds on
the thermalization times of quantum mechanical systems. Joint work
with Stephanie Wehner.
[1] F. Dupuis, M. Berta, J. Wullschleger, and R. Renner,
arXiv:1012.6044v1 (2010).
[2] S. Popescu, A. Short, and A. Winter, Nature Physics 2, 754
(2006).
[3] N. Linden, S. Popescu, A. Short, and A. Winter, New Journal of
Physics 12, 055021 (2010).
[4] A. Harrow and R. Low, Communications in Mathematical Physics
291, 257 (2009).
[5] A. Hutter and S. Wehner, arXiv:1111.3080v3 (2011).