Energy Gap in Saturn’s Rings

Cytokinetic rings mind the gap

In-gap corner states in core-shell polygonal quantum rings

We study Coulomb interacting electrons confined in polygonal quantum rings. We focus on the interplay of localization at the polygon corners and Coulomb repulsion. Remarkably, the Coulomb repulsion allows the formation of in-gap states, i.e., corner-localized states of electron pairs or clusters shifted to energies that were forbidden for non-interacting electrons, but below the energies of cor...

Metastable Black Saturns Combining Everything (1) Becomes

Black Saturns have multiple horizons and so offer a testing ground for the ideas of black hole thermodynamics. In this note, we numerically scan for phases that are in equilibrium by extremizing total entropy in the 2-dimensional moduli space of stationary, singly rotating black Saturns with fixed total mass and angular momentum. On top of the known TH = TR, ΩH = ΩR configurations, we find phas...

Persistent spin currents in mesoscopic Haldane-gap spin rings

Using a modified spin-wave approach, we show that in the presence of an inhomogeneous magnetic field or an in-plane inhomogeneous electric field a mesoscopic antiferromagnetic Heisenberg ring with integer spin ~i.e., a Haldane-gap system! exhibits a persistent circulating spin current. Due to quantum fluctuations the current has a finite limit on the order of (2gmB)c/L at zero temperature, prov...

Beam Loading in High-energy Storage Rings*

The analysis of beam loading in the RF systems olhighenergy storage rings (for example, the PEP e-e+ ring ) is complicated by the fact that the time, Tb, between the passage of successive bunches is comparable to the cavity filling time, Tf. In this paper, beam loading expressions are first summarized for the usual case in which Th << Tt. The theory of phase oscillations in the heavily-bea&loa&...