Many-body multivaluedness of particle-current variance in closed and open cold-atom systems
The quantum variance of an observable is a fundamental quantity in quantum mechanics, and the variance provides additional information other than the average itself. By examining the relation between the particle-current variance $$(\delta J)^2$$ and the average current $$J$$ in both closed and open interacting fermionic systems, we show the emergence of a multi-valued Lissajous curve between $$\delta J$$ and $$J$$ due to interactions. As a closed system we considered the persistent current in a benzene-like lattice enclosing an effective magnetic flux and solved it by exact diagonalization. For the open system, the steady-state current flowing through a few lattice sites coupled to two particle reservoirs was investigated using a Lindblad equation. In both cases, interactions open a loop and change the topology of the corresponding $$\delta J$$-$$J$ Lissajous curve, showing that this effect is model-independent. We finally discuss how the predicted phenomena can be observed in ultracold atoms, thus offering an alternative way of probing the dynamics of many-body systems.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- 89233218CNA000001; AC02-05CH11231
- OSTI ID:
- 1482946
- Alternate ID(s):
- OSTI ID: 1480367; OSTI ID: 1580339
- Report Number(s):
- LA-UR-18-23857; PLRAAN
- Journal Information:
- Physical Review A, Vol. 98, Issue 5; ISSN 2469-9926
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Study of counterintuitive transport properties in the Aubry-André-Harper model via entanglement entropy and persistent current
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journal | November 2019 |
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