"Theory of collective magnetophonon resonance and melting of a field-induced Wigner solid"

Luca V. Delacrétaz: Blaise Goutéraux, Sean A. Hartnoll, and Anna Karlsson; Physical Review B, 08/26/19.

Additional Authors: Blaise Goutéraux, Sean A. Hartnoll, and Anna Karlsson


Electron solid phases of matter are revealed by characteristic vibrational resonances. Sufficiently large magnetic fields can overcome the effects of disorder, leading to a weakly pinned collective mode called the magnetophonon. Consequently, in this regime it is possible to develop a tightly constrained hydrodynamic theory of pinned magnetophonons. The behavior of the magnetophonon resonance across thermal and quantum melting transitions has been experimentally characterized in two-dimensional electron systems. Applying our theory to these transitions we explain several key features of the data. Firstly, violation of the Fukuyama-Lee sum rule as the transition is approached is shown to be a consequence of the non-Lorentzian form taken by the resonance. Secondly, this non-Lorentzian shape is shown to be caused by dissipative channels that become especially important close to melting: proliferating dislocations and uncondensed charge carriers.