Abstract

Ever since the seminal torsional oscillator (TO) measurements of Kim and Chan which suggested the existence of a phase transition in solid 4He, from normal to a ‘supersolid’ state below a critical temperature Tc= 200 mK, there has been an unprecedented amount of excitement and research activity aimed at better understanding this phase. Despite much work, this remarkable phase has yet to be independently confirmed by conventional scattering techniques, such as neutron scattering. We have carried out a series of neutron scattering measurements, which we here review, aimed at observing Bose-Einstein condensation (BEC) in solid 4He at temperatures below Tc. In bulk liquid 4He, the appearance of BEC below Tλ signals the onset of superfluidity. The observation of a condensate fraction in the solid would provide an unambiguous confirmation for ‘supersolidity’. Although, our measurements have not yet revealed a non-zero condensate fraction or algebraic off diagonal long-range order n0 in solid 4He down to 65 mK, i.e. n0=(0±0.3)%, our search for BEC and its corollaries continues with improved instrumentation.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.