On effective theory of superfluid phonons
| Autor: | Lasha Berezhiani |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
High Energy Physics - Theory
Physics Nuclear and High Energy Physics 010308 nuclear & particles physics Friction force Phonon Order (action) FOS: Physical sciences 01 natural sciences lcsh:QC1-999 Superfluidity High Energy Physics - Phenomenology High Energy Physics - Phenomenology (hep-ph) High Energy Physics - Theory (hep-th) Quantum Gases (cond-mat.quant-gas) Quantum mechanics 0103 physical sciences Effective field theory Proper treatment Supersonic speed Condensed Matter - Quantum Gases 010306 general physics lcsh:Physics |
| Zdroj: | Physics Letters B, Vol 805, Iss, Pp-(2020) Physics Letters Physics Letters B |
| ISSN: | 0370-2693 |
| Popis: | It is shown that the standard effective field theory of non-relativistic superfluids, which includes only the leading order action in derivative expansion, is in general inadequate for studying supersonic processes. Namely, for a proper treatment of the latter the phonons with momenta greater than $mc_s$ are relevant at times (with $m$ being the mass of the superfluid constituent and $c_s$ denoting the sound-speed), which lie beyond the regime of validity of the naive effective theory mentioned above. This is demonstrated on a concrete example by recovering the known expression for the friction force as a process of radiating phonons by a supersonic perturber. In particular, when the impurity is heavier than superfluid constituents, it is indeed necessary to extend the non-relativistic effective theory of superfluids to include high-derivative corrections. For the light perturber, however, there is a window of velocities for which high-derivative corrections are irrelevant. 11 pages |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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