Transport equation for 2D electron liquid under microwave radiation plus magnetic field and the Zero Resistance State

A general transport equation for the center of mass motion is constructed to study transports of electronic system under uniform magnetic field and microwave radiation. The equation is applied to study 2D electron system in the limit of weak disorder where negative resistance instability is observed when the radiation field is strong enough. A solution of the transport equation with spontaneous AC current is proposed to explain the experimentally observed Radiation-Induced Zero Resistance State.Comment: 9 pages, 1 figur

Stabilization of Majorana modes in vortices in the superconducting phase of topological insulators using topologically trivial bands

If superconductivity is induced in the metallic surface states of topological insulators via proximity, Majorana modes will be trapped on the vortex cores. The same effects hold for doped topological insulators which become bulk s-wave superconductors as long as the doping does not exceed a critical values $\mu^{\pm}_c.$ It is this critical chemical potential at which the material forgets it arose from a band-inverted topological insulator; it loses its topological \emph{imprint.} For the most common classes of topological insulators, which can be modeled with a minimal 4-band Dirac model the values of $\mu^{\pm}_c$ can be easily calculated, but for materials with more complicated electronic structures such as HgTe or ScPtBi the result is unknown. We show that due to the hybridization with an additional Kramers' pair of topologically trivial bands the topological imprint of HgTe-like electronic structures (which includes the ternary Heusler compounds) can be widely extended for p-doping. As a practical consequence we consider the effects of such hybridization on the range of doping over which Majorana modes will be bound to vortices in superconducting topological insulators and show that the range is strongly extended for p-doping, and reduced for n-doping. This leaves open the possibility that other topological phenomena may be stabilized over a wider range of doping.Comment: 5 pages, 1 figure, Accepted for publication in Physical Review Letter

Transverse momentum distribution of vector mesons produced in ultraperipheral relativistic heavy ion collisions

We study the transverse momentum distribution of vector mesons produced in ultraperipheral relativistic heavy ion collisions (UPCs). In UPCs there is no strong interaction between the nuclei and the vector mesons are produced in photon-nucleus collisions where the (quasireal) photon is emitted from the other nucleus. Exchanging the role of both ions leads to interference effects. A detailed study of the transverse momentum distribution which is determined by the transverse momentum of the emitted photon, the production process on the target and the interference effect is done. We study the total unrestricted cross section and those, where an additional electromagnetic excitation of one or both of the ions takes place in addition to the vector meson production, in the latter case small impact parameters are emphasized.Comment: 12 pages, REVTeX manuscrip

GeV Majorana Neutrinos in Top-quark Decay at the LHC

We explore the \Delta L=2 same-sign dilepton signal from top-quark decay via a Majorana neutrino at the LHC in the top anti-top pair production samples. The signature is same-sign dilepton plus multi-jets with no significant missing energy. The most optimistic region lies where the Majorana neutrino mass is between 15-65 GeV. For 300 fb^-1 integrated luminosity, it is possible to probe S_{ij}, the effective mixing parameter, to order of 10^-5.Comment: 15 pages, 8 figure