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Contributed by Dam Thanh Son, September 17, 2020 (sent for review August 20, 2020; reviewed by Joseph Carlson and Boris Svistunov)
Significance
Predicting the properties of a quantum-mechanical system of many interacting particles is a major goal of modern science and an outstanding challenge. We consider a compact and versatile model which captures the essential features of a broad class of systems made of particles obeying Bose–Einstein statistics and which allows one to systematically dial up the effect of quantum entanglement in the presence of particle interaction by tuning a single parameter. We are able to obtain exact numerical results for the phase diagrams of these systems. Possible directions for experimental realization of the predictions are discussed.
Abstract
We present a comprehensive theoretical study of the phase diagram of a system of many Bose particles interacting with a two-body central potential of the so-called Lennard-Jones form. First-principles path-integral computations are carried out, providing essentially exact numerical results on the thermodynamic properties. The theoretical model used here provides a realistic and remarkably general framework for describing simple Bose systems ranging from crystals to normal fluids to superfluids and gases. The interplay between particle interactions on the one hand and quantum indistinguishability and delocalization on the other hand is characterized by a single quantumness parameter, which can be tuned to engineer and explore different regimes. Taking advantage of the rare combination of the versatility of the many-body Hamiltonian and the possibility for exact computations, we systematically investigate the phases of the systems as a function of pressure (P) and temperature (T), as well as the quantumness parameter. We show how the topology of the phase diagram evolves from the known case of 4He, as the system is made more (and less) quantum, and compare our predictions with available results from mean-field theory. Possible realization and observation of the phases and physical regimes predicted here are discussed in various experimental systems, including hypothetical muonic matter.
- statistical physics
- quantum many-body physics
- quantum fluids and solids
- Bose–Einstein condensation
- superfluidity
Footnotes
- ↵1To whom correspondence may be addressed. Email: ykora{at}ualberta.ca or dtson{at}uchicago.edu.
Author contributions: Y.K., M.B., D.T.S., and S.Z. designed research, performed research, contributed new reagents/analytic tools, analyzed data, and wrote the paper.
Reviewers: J.C., Los Alamos National Laboratory; and B.S., University of Massachusetts Amherst.
The authors declare no competing interest.
See online for related content such as Commentaries.
Data Availability.
There are no data underlying this work.
Published under the PNAS license.
References
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Tuning the quantumness of simple Bose systems: A universal phase diagram
Article Classifications
- Physical Sciences
- Physics
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