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arXiv · quant-ph/0501018

Ground State Entanglement Energetics

M. Buttiker·A. N. Jordan
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Abstract

We consider the ground state of simple quantum systems coupled to an environment. In general the system is entangled with its environment. As a consequence, even at zero temperature, the energy of the system is not sharp: a projective measurement can find the system in an excited state. We show that energy fluctuation measurements at zero temperature provide entanglement information. For two-state systems which exhibit a persistent current in the ground state, energy fluctuations and persistent current fluctuations are closely related. The harmonic oscillator serves to illustrate energy fluctuations in a system with an infinite number of states. In addition to the energy distribution we discuss the energy-energy time-correlation function in the zero-temperature limit.

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M. Buttiker, A. N. Jordan. 2005-01-04. Ground State Entanglement Energetics. https://doi.org/10.1016/j.physe.2005.05.024

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