Abstract
We show how many-body ground state entanglement information may be extracted from subsystem energy measurements at zero temperature. Generically, the larger the measured energy fluctuations are, the larger the entanglement is. Examples are given with the two-state system and the harmonic oscillator. Comparisons made with recent qubit experiments show that this type of measurement provides another method to quantify entanglement with the environment.
- Received 17 November 2003
DOI:https://doi.org/10.1103/PhysRevLett.92.247901
©2004 American Physical Society