PIRSA:15100116

Non-standard thermalization in critical quench in 2D

Mandal, G. (2015). Non-standard thermalization in critical quench in 2D. Perimeter Institute. https://pirsa.org/15100116

Mandal, Gautam. Non-standard thermalization in critical quench in 2D. Perimeter Institute, Oct. 27, 2015, https://pirsa.org/15100116 

          @misc{ pirsa_PIRSA:15100116,
            doi = {10.48660/15100116},
            url = {https://pirsa.org/15100116},
            author = {Mandal, Gautam},
            keywords = {Quantum Fields and Strings},
            language = {en},
            title = {Non-standard thermalization in critical quench in 2D},
            publisher = {Perimeter Institute},
            year = {2015},
            month = {oct},
            note = {PIRSA:15100116 see, \url{https://pirsa.org}}
          }

Gautam Mandal

Tata Institute of Fundamental Research (TIFR)

Talk number
PIRSA:15100116
Collection
Talk Type
Subject
Abstract

We consider quantum quench from a gapped to a gapless system in 1+1 dimensions. We 

provide a rigorous proof of the thermalization of the reduced density matrix, hence that of

an arbitrary string of local operators in an interval. In case the system is integrable, the "thermalization" leads to a generalized Gibbs ensemble (GGE). We model the critical quench in terms of an initial state in terms of a conformal boundary state deformed by exponential cutoffs involving hamiltonian and other charges. We justify this choice of the initial state by explicitly

deriving it in free boson and free fermion systems with time-dependent mass. A surprising result we find is that for generic quenches and observables the higher charges remain 

important even if the initial gap is arbitrarily high, contrary to standard RG expectations.

( based on hep-th/1501.04580  and a couple of upcoming papers)