7 research outputs found
Parity-Affected Persistent Currents in Superconducting Nanorings
We argue that at sufficiently low temperatures T superconducting parity
effect may strongly influence equilibrium persistent currents (PC) in isolated
superconducting nanorings containing a weak link with few conducting modes. For
a single channel quantum point contact at T=0 we predict a novel effect of
parity-induced blocking of PC. In nanorings with SNS junctions a -state
can occur for the odd number of electrons. Changing this number from even to
odd yields spontaneous supercurrent in the ground state of such rings without
any externally applied magnetic flux.Comment: Published versio
Early Dark Energy with Power-law F(R) Gravity
We study a power-law gravity with an early dark energy term, that can
describe both the early-time and the late-time acceleration of the Universe. We
confront this scenario with recent observational data including the Pantheon
Type Ia supernovae, measurements of the Hubble parameter (Cosmic
Chronometers), data from Baryon Acoustic Oscillations and standard rulers data
from the Cosmic Microwave Background (CMB) radiation. The model demonstrates
some achievements in confronting with these observations and can be compared
with the -Cold-Dark-Matter model. In particular, in both models we
obtain very close estimates for the Hubble constant , but it is not true
for . The early dark energy term supports viability of the
considered gravity model.Comment: PLB Accepte
Parity effect and spontaneous currents in superconducting nanorings
New physical effects emerge from an interplay between the electron parity
number and persistent currents in superconducting nanorings. An odd electron,
being added to the ring, produces a countercurrent which may substantially
modify the ground state properties of the system. In superconducting nanorings
with an embedded normal metal layer a novel ``-junction'' state can
occur for the odd number of electrons. Changing this number from even to odd
yields spontaneous supercurrent in the ground state of such rings without any
externally applied magnetic flux. Further peculiar features of the parity
effect are expected in structures with resonant electron transport across the
weak link.Comment: 9 pages, 5 figures. Invited talk at the International Conference
"Frontiers of Quantum and Mesoscopic Thermodynamics", Prague, July 200
Scientific program of DERICA — prospective accelerator and storage ring facility for radioactive ion beam research
Studies of radioactive ions (RIs) are the most thriving field of low-energy nuclear physics. In this paper, the concept and the scientific agenda of the prospective accelerator and storage ring facility for RI beam (RIB) research are proposed for a large-scale international project based at the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research. The motivation for the new facility is discussed and its characteristics are briefly presented and shown to be comparable to those of advanced world centers, the so-called "RIB factories". In the project, the emphasis is made on studies with short-lived RIBs in storage rings. Aunique feature of the project is the possibility of studying electron-RI interactions in a collider experiment to determine the fundamental properties of nuclear matter, in particular, electromagnetic form factors of exotic nuclei