SP Seminar @ICTP Stasi Tuesday 31 July at 11am - M.A. RAJAPOUR

[CM Section]

Joint ICTP/SISSA Statistical Physics Seminar

Tuesday 31 July at 11:00 a.m.
Luigi Stasi Seminar Room, first floor, Leonardo Building

Speaker:
Mohammad Ali RAJAPOUR (Instituto de Fisica,
Univ. Federal Fluminense, Neteroi, Brazil)

Title:
Area-law and Universality in the Statistics of the Subsystem Energy

_Abstract: _

__Consider a quantum chain in its ground state and then take a subdomain 
of this system with natural truncated hamiltonian. Since the total 
hamiltonian does not commute with the truncated hamiltonian the 
subsystem can be in one of its eigenenergies with different 
probabilities. Since the global energy eigenstates are locally close to 
diagonal in the local energy eigenbasis we argue that the Shannon(Renyi) 
entropy of these probabilities follows an area-law for the gapped 
systems. When the system is at the critical point the Shannon(Renyi) 
entropy follows a logarithmic behaviour with a universal coefficient.

Our results show that the Shannon(Renyi) entropy of the subsystem 
energies closely mimics the behaviour of the entanglement entropy in 
quantum chains. We support the arguments by detailed numerical 
calculations performed on the transverse field XY-chain.** **

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