Energies and collapse times of symmetric and symmetry-breaking states of finite systems with a U(1) symmetry

Details Energies and collapse times of symmetric and symmetry-breaking states of finite systems with a U(1) symmetry Energies and collapse times of symmetric and symmetry-breaking states of finite systems with a U(1) symmetry

2001-04-17

arxiv.org/abs/cond-mat/0104284v2

Phys. Rev. E64, 056121 (2001)

Physics

Condensed Matter

Statistical Mechanics

In the revised manuscript, Eq. (22), Ref. [8], and Notes [13], [15] and [17] have been added

Scientific paper

10.1103/PhysRevE.64.056121

We study quantum systems of volume V, which will exhibit the breaking of a U(1) symmetry in the limit of V \to \infty, when V is large but finite. We estimate the energy difference between the `symmetric ground state' (SGS), which is the lowest-energy state that does not breaks the symmetry, and a `pure phase vacuum' (PPV), which approaches a symmetry-breaking vacuum as V \to \infty. Under some natural postulates on the energy of the SGS, it is shown that PPVs always have a higher energy than the SGS, and we derive a lower bound of the excess energy. We argue that the lower bound is O(V^0), which becomes much larger than the excitation energies of low-lying excited states for a large V. We also discuss the collapse time of PPVs for interacting many bosons. It is shown that the wave function collapses in a microscopic time scale, because PPVs are not energy eigenstates. We show, however, that for PPVs the expectation value of any observable, which is a finite polynomial of boson operators and their derivatives, does not collapse for a macroscopic time scale. In this sense, the collapse time of PPVs is macroscopically long.

Affiliated with

Also associated with

No associations

Rating

Energies and collapse times of symmetric and symmetry-breaking states of finite systems with a U(1) symmetry does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Energies and collapse times of symmetric and symmetry-breaking states of finite systems with a U(1) symmetry, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Energies and collapse times of symmetric and symmetry-breaking states of finite systems with a U(1) symmetry will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-483995