Theory for superfluidity in a Bose system
| dc.creator | Hao, Zhidong | |
| dc.date | 2008-07-09 | |
| dc.date | 2009-03-12 | |
| dc.date.accessioned | 2026-07-07T12:51:12Z | |
| dc.date.available | 2026-07-07T12:51:12Z | |
| dc.description | We present a microscopic theory for superfluidity in an interacting many-particle Bose system (such as liquid $^4$He). We show that, similar to superconductivity in superconductors, superfluidity in a Bose system arises from pairing of particles of opposite momenta. We show the existence of an energy gap in single-particle excitation spectrum in the superfluid state and the existence of a specific heat jump at the superfluid transition. We derive an expression for superfluid particle density $n_s$ as a function of temperature $T$ and superfluid velocity ${\bf v}_s$. We show that superfluid-state free energy density $F$ is an increasing function of $v_s$ (i.e., $\partial F/\partial v_s > 0$), which indicates that a superfluid has a tendency to remain motionless (this result qualitatively explains the Hess-Fairbank effect, which is analogous to the Meissner effect in superconductors). We further speculate the existence of the equation ${\bf j}=-Λ\nabla\times \text{\boldmath $ω$}$, where ${\bf j} = n_s{\bf v}_s$ is the superfluid current density, $\text{\boldmath $ω$}=\nabla\times {\bf v}_s$ the superfluid vorticity, and $Λ$ a positive constant (with the help of this equation, the Hess-Fairbank effect can be quantitatively described). | |
| dc.description | 17 pages 12 figures; revised; and added quatitative description of Hess-Fiarbank effect | |
| dc.identifier | https://arxiv.org/abs/0807.1503 | |
| dc.identifier | http://arxiv.org/abs/0807.1503 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/222916 | |
| dc.subject | Superconductivity | |
| dc.title | Theory for superfluidity in a Bose system | |
| dc.type | text |