zero-soundhttp://www.oed.com/dictionary/zero-sound_n%3Ftab%3Dmeaning_and_usezero sound, n.
Revised 2018

zero soundnoun

  1. 1957–
    The propagation of waves through a Fermi liquid, caused by deformation of the Fermi surface rather than collisions between particles; see sound n.3 1d.
    1. 1957
      It is shown..that in a Fermi liquid at absolute zero other waves can be propagated; these differ in nature from ordinary sound, and we shall call them waves of ‘zero sound’.
      translation of L. D. Landau in Soviet Physics: JETP vol. 5 102/1
    2. 1999
      These bosonic oscillative modes are known as different harmonics of the zero sound.
      Proceedings of National Academy of Sciences U.S.A. vol. 96 6042/2
    3. 2015
      Whereas conventional sound travels at a speed below the Fermi velocity, zero sound is ‘supersonic’, traveling at speeds in excess of the Fermi velocity.
      P. Coleman, Introd. Many-body Physics vi.150

Originally published as part of the entry for zero, n. & adj.

zero, n. & adj. was revised in June 2018.