Vibrational Dynamics of Amorphous Quantum Solids

1. Vibrational Dynamics of Amorphous Quantum Solids Research Details Amorphous solid helium can be created by confining the solid in porous media. We have measured the dynamics of this quantum, highly anharmonic solid for the first time. The dynamics of an amorphous quantum solid is found to be very similar to that of crystalline quantum solids, a similarity that is found in more classical and harmonic solids. Upper: Phase diagram of helium in porous MCM-41 (47 Å diameter) and gelsil ( 25 Å) showing the confined (amorphous) solid phase. Lower: The dynamical density of states (a) T = 0.05 K, amorphous solid in the pores plus crystalline solid background and (b) T= 1.60 K, liquid in the pores and the same background. The amorphous solid DOS at low energy is a smooth function of energy, ω, as in a polycrystalline solid. J Bossy, J Ollivier, and H Schober, HR Glyde, Physical Review B 86, 224503 (2012). University of Delaware and the Institut Laue Langevin, France Scientific Achievement Amorphous solid helium has been stabilized in small pore, porous media. The density of vibrational states (DOS) of this highly quantum amorphous solid is shown to be similar to that in polycrystalline solids as found for classical solids. Significance and Impact Amorphous quantum solid helium is predicted to be a supersolid (a solid with Bose-Einstein condensation and superflow). We show that the dynamics of this quantum solid is smooth in energy at low energy as found in quantum and classical crystals. No well defined or sharp modes suggesting superflow are observed. .