12,421 research outputs found
Theory of control of spin/photon interface for quantum networks
A cavity coupling a charged nanodot and a fiber can act as a quantum
interface, through which a stationary spin qubit and a flying photon qubit can
be inter-converted via cavity-assisted Raman process. This Raman process can be
controlled to generate or annihilate an arbitrarily shaped single-photon
wavepacket by pulse-shaping the controlling laser field. This quantum interface
forms the basis for many essential functions of a quantum network, including
sending, receiving, transferring, swapping, and entangling qubits at
distributed quantum nodes as well as a deterministic source and an efficient
detector of a single photon wavepacket with arbitrarily specified shape and
average photon number. Numerical study of noise effects on the operations shows
high fidelity.Comment: 4 pages, 2 figure
Deduction of the quantum numbers of low-lying states of 6-nucleon systems based on symmetry
The inherent nodal structures of the wavefunctions of 6-nucleon systems have
been investigated. The existence of a group of six low-lying states dominated
by L=0 has been deduced. The spatial symmetries of these six states are found
to be mainly {4,2} and {2,2,2}.Comment: 8 pages, no figure
Theory for electric dipole superconductivity with an application for bilayer excitons
Exciton superfluid is a macroscopic quantum phenomenon in which large
quantities of excitons undergo the Bose-Einstein condensation. Recently,
exciton superfluid has been widely studied in various bilayer systems. However,
experimental measurements only provide indirect evidence for the existence of
exciton superfluid. In this article, by viewing the exciton in a bilayer system
as an electric dipole, we provide a general theory for the electric dipole
superconductivity, and derive the London-type and Ginzburg-Landau-type
equations for the electric dipole superconductors. By using these equations, we
discover the Meissner-type effect and the electric dipole current Josephson
effect. These effects can provide direct evidence for the formation of the
exciton superfluid state in bilayer systems and pave new ways to drive an
electric dipole current.Comment: 10 pages, 5 figures, 1 Supplementary Informatio
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