Abstract
Considering any Hamiltonian, any initial state, and measurements with a small number of possible outcomes compared to the dimension, we show that most measurements are already equilibrated. To investigate nontrivial equilibration we therefore consider a restricted set of measurements. When the initial state is spread over many energy levels, and we consider the set of observables for which this state is an eigenstate, most observables are initially out of equilibrium yet equilibrate rapidly. Moreover, all twooutcome measurements, where one of the projectors is of low rank, equilibrate rapidly.
Original language  English 

Article number  012121 
Journal  Physical Review E: Statistical, Nonlinear, and Soft Matter Physics 
Volume  90 
Issue number  1 
DOIs  
Publication status  Published  22 Jul 2014 
Bibliographical note
Main Text: 5 pages, 1 figure. Appendices: 7 pages, 1 figureKeywords
 quantph
 condmat.statmech
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Professor Noah Linden
 Fundamental Bioscience
 School of Mathematics  Professor of Theoretical Physics
 The Bristol Centre for Nanoscience and Quantum Information
 Applied Mathematics
 Quantum Information Theory
 Mathematical Physics
Person: Academic , Member

Dr A J Short
Person: Academic , Member