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Эта публикация цитируется в 36 научных статьях (всего в 36 статьях)
МЕТОДЫ ТЕОРЕТИЧЕСКОЙ ФИЗИКИ
On the broken time translation symmetry in macroscopic
systems: precessing states and off-diagonal long-range order
G. E. Volovikab a Aalto University, School of Science and Technology
b L. D. Landau Institute for Theoretical Physics, Russian Academy of Sciences
Аннотация:
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 dihotomy is resolved in systems
with quasi-ODLRO.
These systems have two well separated relaxation times: the relaxation time $\tau_Q$ of
the charge $Q$ and the energy relaxation time $\tau_E$. If $\tau_Q \gg \tau_E$, 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 $\tau_Q \rightarrow \infty$,
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
$^4$He, Bose–Einstein condensation of magnons (phase coherent spin precession) and
precessing vortices.
Поступила в редакцию: 17.09.2013
Образец цитирования:
G. E. Volovik, “On the broken time translation symmetry in macroscopic
systems: precessing states and off-diagonal long-range order”, Письма в ЖЭТФ, 98:8 (2013), 549–553; JETP Letters, 98:8 (2013), 491–495
Образцы ссылок на эту страницу:
https://www.mathnet.ru/rus/jetpl3553 https://www.mathnet.ru/rus/jetpl/v98/i8/p549
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