9 research outputs found
Energy of a single electron in gaseous media
The so-called «optical» approximation in the theory of electron energy spectrum in the presence of scattering
centers with positive scattering length randomly distributed with the average density ng is considered
for a number of inert gases. The average minimal energy W of a single electron calculated beyond the optical
approximation reveals a behavior qualitatively different from that of the same quantity W₀ derived within the
optical approximation. Results of calculations are in qualitative agreement with experimental data available
for theW(ng) dependence for different cryogenic gases
Teleportation of the Relativistic Quantum Field
The process of teleportation of a completely unknown one-particle state of a
free relativistic quantum field is considered. In contrast to the
non-relativistic quantum mechanics, the teleportation of an unknown state of
the quantum field cannot be in principle described in terms of a measurement in
a tensor product of two Hilbert spaces to which the unknown state and the state
of the EPR-pair belong. The reason is of the existence of a cyclic (vacuum)
state common to both the unknown state and the EPR-pair. Due to the common
vacuum vector and the microcausality principle (commutation relations for the
field operators), the teleportation amplitude contains inevitably contributions
which are irrelevant to the teleportation process. Hence in the relativistic
theory the teleportation in the sense it is understood in the non-relativistic
quantum mechanics proves to be impossible because of the impossibility of the
realization of the appropriate measurement as a tensor product of the
measurements related to the individual subsystems so that one can only speak of
the amplitude of the propagation of the field as a whole.Comment: 11 page
Photon Frequency Entanglement Swapping
We propose a simple non-linear crystal based optical scheme for experimental
realization of the frequency entanglement swapping between the photons
belonging to two independent biphotons.Comment: 5 pages, 1 figure. Submitted to Phys.Lett.
Spontaneous Coherence and Collective Modes in Double-Layer Quantum Dot Systems
We study the ground state and the collective excitations of
parabolically-confined double-layer quantum dot systems in a strong magnetic
field. We identify parameter regimes where electrons form maximum density
droplet states, quantum-dot analogs of the incompressible states of the bulk
integer quantum Hall effect. In these regimes the Hartree-Fock approximation
and the time-dependent Hartree-Fock approximations can be used to describe the
ground state and collective excitations respectively. We comment on the
relationship between edge excitations of dots and edge magneto-plasmon
excitations of bulk double-layer systems.Comment: 20 pages (figures included) and also available at
http://fangio.magnet.fsu.edu/~jhu/Paper/qdot_cond.ps, replaced to fix figure