220 research outputs found
Observation of the Inverse Cotton-Mouton Effect
We report the observation of the Inverse Cotton-Mouton Effect (ICME) i.e. a
magnetization induced in a medium by non resonant linearly polarized light
propagating in the presence of a transverse magnetic field. We present a
detailed study of the ICME in a TGG crystal showing the dependence of the
measured effect on the light intensity, the optical polarization, and on the
external magnetic field. We derive a relation between the Cotton-Mouton and
Inverse Cotton-Mouton effects that is roughly in agreement with existing
experimental data. Our results open the way to applications of the ICME in
optical devices
Zero-point momentum in Complex media
In this work we apply field regularization techniques to formulate a number
of new phenomena related to momentum induced by electromagnetic zero-point
fluctuations. We discuss the zero-point momentum associated with
magneto-electric media, with moving media, and with magneto-chiral media.Comment: submitted to EPJ
Chirality in charge-transfer salts of BEDT-TTF of tris(oxalato)chromate(III)
Crystallisation from chiral electrolyte (R)-(â)-carvone has produced three new chiral semiconducting salts of BEDT-TTF from racemic anion tri(oxalato)chromate(III)
Laser induced breakdown of the magnetic field reversal symmetry in the propagation of unpolarized light
We show how a medium, under the influece of a coherent control field which is
resonant or close to resonance to an appropriate atomic transition, can lead to
very strong asymmetries in the propagation of unpolarized light when the
direction of the magnetic field is reversed. We show how EIT can be used to
mimic effects occuring in natural systems and that EIT can produce very large
asymmetries as we use electric dipole allowed transitions. Using density matrix
calculations we present results for the breakdown of the magnetic field
reversal symmetry for two different atomic configurations.Comment: RevTex, 6 pages, 10 figures, Two Column format, submitted to Phys.
Rev.
Universal magnetic structure of the half-magnetization phase in Cr-based spinels
Using an elastic neutron scattering technique under a pulsed magnetic field
up to 30 T, we determined the magnetic structure in the half-magnetization
plateau phase in the spinel CdCrO. The magnetic structure has a cubic
32 symmetry, which is the same as that observed in HgCrO. This
suggests that there is a universal field induced spin-lattice coupling
mechanism at work in the Cr-based spinels.Comment: 4 pages, 4 figure
Transverse Momentum Transfer in Atom-Light Scattering
We predict a photon Hall effect in the optical cross-section of atomic
hydrogen, which is caused by the interference between an electric quadrupole
transition and an electric dipole transition from the ground state to
and . This induces a magneto-transverse acceleration
comparable to a fraction of . In atoms with a two level electric dipole
transition, a much smaller transverse force is generated only when the atom is
moving
About the connection between vacuum birefringence and the light-light scattering amplitude
Birefringence phenomena stemming from vacuum polarization are revisited in
the framework of coherent scattering. Based on photon-photon scattering, our
analysis brings out the direct connection between this process and vacuum
birefringence. We show how this procedure can be extended to the Kerr and the
Cotton-Mouton birefringences in vacuum, thus providing a unified treatment of
various polarization schemes, including those involving static fields
Chirality effects in carbon nanotubes
We consider chirality related effects in optical, photogalvanic and
electron-transport properties of carbon nanotubes. We show that these
properties of chiral nanotubes are determined by terms in the electron
effective Hamiltonian describing the coupling between the electron wavevector
along the tube principal axis and the orbital momentum around the tube
circumference. We develop a theory of photogalvanic effects and a theory of
d.c. electric current, which is linear in the magnetic field and quadratic in
the bias voltage. Moreover, we present analytic estimations for the natural
circular dichroism and magneto-spatial effect in the light absorption.Comment: 23 pages, 3 figure
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