6 research outputs found
Realization of a superconducting atom chip
We have trapped rubidium atoms in the magnetic field produced by a
superconducting atom chip operated at liquid Helium temperatures. Up to
atoms are held in a Ioffe-Pritchard trap at a distance of 440
m from the chip surface, with a temperature of 40 K. The trap
lifetime reaches 115 s at low atomic densities. These results open the way to
the exploration of atom--surface interactions and coherent atomic transport in
a superconducting environment, whose properties are radically different from
normal metals at room temperature.Comment: Submitted to Phys. Rev. Let
Effect of weak magnetic field on polariton-electron scattering in semiconductor microcavities
We theoretically calculate the polariton linewidth associated with the
polariton-electron scattering in a microcavity in presence of a magnetic field
perpendicular to the microcavity plane. It is shown that the polariton
linewidth oscillates as a function of the magnetic field magnitude and the
polariton-electron scattering rate can be not only decreased but also increased
by the magnetic field. The possible applications of such an effect are
discussed.Comment: LaTex, 6 pages, 3 figure
Electron-polariton scattering in semiconductor microcavities
In semiconductor microcavities, electron-polariton scattering has been proposed as an efficient process that can drive polaritons from the bottleneck region to the ground state, achieving Bose amplification of the optical emission. We present clear experimental observation of this process in a structure that allows control of the electron density and we report substantial enhancement of photoluminescence. We show that this enhancement is more effective at higher temperatures due to the different way that electron scattering processes either broaden or relax polaritons
Electron-Polariton scattering, beneficial and detrimental effects
We study the effects of electron-polariton scattering in a semiconductor microcavity that allows control of the electron density. We show that this process can efficiently drive polaritons to the ground polariton state and that it is more effective whenever the relaxation bottleneck is present on the LP branch
Teaching polaritons new tricks
Semiconductor microcavities have attracted much recent interest because they utilize simultaneously 2D confinement of both excitons and photons in the same heterostructure. Strong coupling of these two states produces unique dynamics that can be well described in a quasiparticle state, the cavity polaritons. Their dispersion relation is dramatically modified with an apparent trap in k-space offering exciting new possibilities for tailoring nonlinear optical properties in microcavities. The reduced density of states inside the trap allows the macroscopic occupancy of polaritons producing much of the new physics. This paper describes recent work on nonlinear effects in semiconductor microcavities including stimulated scattering, parametric oscillation and non-equilibrium phase transition. By teaching polaritons new tricks, both fundamental questions about their bosonic nature can be answered and practical applications in a variety of optoelectronic and interferometric devices can be found