We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
On the broken time translation symmetry in macroscopic systems: Precessing states and off-diagonal long-range order.
- Authors
Volovik, G.
- Abstract
The broken symmetry state with off-diagonal long-range order (ODLRO), which is characterized by the vacuum expectation value of the operator of creation of the conserved quantum number Q, has the time-dependent order parameter. However, the breaking of the time translation symmetry is observable only if the charge Q is not strictly conserved and may decay. This dichotomy is resolved in systems with quasi-ODLRO. These systems have two well separated relaxation times: the relaxation time τ of the charge Q and the energy relaxation time τ. If τ ≫ τ, the perturbed system relaxes first to the state with the ODLRO, which persists for a long time and finally relaxes to the full equilibrium static state. In the limit τ Q → ∞, but not in the strict limit case when the charge Q is conserved, the intermediate ODLRO state can be considered as the ground state of the system at fixed Q with the observable spontaneously broken time translation symmetry. Examples of systems with quasi-ODLRO are provided by superfluid phase of liquid He, Bose-Einstein condensation of magnons (phase coherent spin precession) and precessing vortices.
- Subjects
SYMMETRY breaking; MICROSCOPY; QUANTUM numbers; VACUUM; ELECTRIC charge; GROUND state (Quantum mechanics); COHERENCE (Physics); BOSE-Einstein condensation
- Publication
JETP Letters, 2013, Vol 98, Issue 8, p491
- ISSN
0021-3640
- Publication type
Article
- DOI
10.1134/S0021364013210133