TY - JOUR
T1 - Eigenstate thermalization and representative states on subsystems
AU - Khemani, Vedika
AU - Chandran, Anushya
AU - Kim, Hyungwon
AU - Sondhi, Shivaji Lal
N1 - Publisher Copyright:
© 2014 American Physical Society.
PY - 2014/11/17
Y1 - 2014/11/17
N2 - We consider a quantum system AB made up of degrees of freedom that can be partitioned into spatially disjoint regions A and B. When the full system is in a pure state in which regions A and B are entangled, the quantum mechanics of region A described without reference to its complement is traditionally assumed to require a reduced density matrix on A. While this is certainly true as an exact matter, we argue that under many interesting circumstances expectation values of typical operators anywhere inside A can be computed from a suitable pure state on A alone, with a controlled error. We use insights from quantum statistical mechanics - specifically the eigenstate thermalization hypothesis (ETH) - to argue for the existence of such "representative states."
AB - We consider a quantum system AB made up of degrees of freedom that can be partitioned into spatially disjoint regions A and B. When the full system is in a pure state in which regions A and B are entangled, the quantum mechanics of region A described without reference to its complement is traditionally assumed to require a reduced density matrix on A. While this is certainly true as an exact matter, we argue that under many interesting circumstances expectation values of typical operators anywhere inside A can be computed from a suitable pure state on A alone, with a controlled error. We use insights from quantum statistical mechanics - specifically the eigenstate thermalization hypothesis (ETH) - to argue for the existence of such "representative states."
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U2 - 10.1103/PhysRevE.90.052133
DO - 10.1103/PhysRevE.90.052133
M3 - Article
C2 - 25493765
AN - SCOPUS:84912567468
SN - 1539-3755
VL - 90
JO - Physical Review E - Statistical, Nonlinear, and Soft Matter Physics
JF - Physical Review E - Statistical, Nonlinear, and Soft Matter Physics
IS - 5
M1 - 052133
ER -