Related papers: Drag in paired electron-hole layers
Several recent experiments have reported an anomalous temperature dependence of the Coulomb drag effect in electron-hole bilayers. Motivated by these puzzling data, we study theoretically a low-density electron-hole bilayer, where electrons…
Bilayer electron-hole systems undergo excitonic condensation when the distance d between the layers is smaller than the typical distance between particles within a layer. All excitons in this condensate have a fixed dipole moment which…
We explain the strong interlayer drag resistance observed at low temperatures in bilayer electron-hole systems in terms of an interplay between local electron-hole-pair condensation and disorder-induced carrier density variations. Smooth…
We study the Coulomb drag effect in double layer electronic systems with local tunneling links. The possibility of tunneling between the layers leads to a pronounced exchange contribution to the transconductance, which is negative and…
Motivated by recent experiments of Pillarisetty {\it et al}, \prl {\bf 90}, 226801 (2003), we present a theory of drag in electronic double layers at low electron concentration. We show that the drag effect in such systems is anomolously…
The advancement of fabrication and lithography techniques of semiconductors have made it possible to study bi-layer systems made of two electronic layers separated by distances of several hundred Angstroms. In this situation the electrons…
We report electrical transport measurements on GaAs/AlGaAs based electron-hole bilayers. These systems are expected to make a transition from a pair of weakly coupled two-dimensional systems to a strongly coupled exciton system as the…
A low-temperature upturn of the Coulomb drag resistivity measured in an undoped electron-hole bilayer (uEHBL) device, possibly manifesting from exciton formation or condensation, was recently observed. The effects of density imbalance on…
Coulomb drag is a process whereby the repulsive interactions between electrons in spatially separated conductors enable a current flowing in one of the conductors to induce a voltage drop in the other. If the second conductor is part of a…
Using Diffusion Monte Carlo simulations we have investigated the ground state of a symmetric electron-hole bilayer and determined its phase diagram at T=0. We find clear evidence of an excitonic condensate, whose stability however is…
The transresistance and the Hall transresistance of dirty two-dimensional bi-layer systems in the presence of tunneling bridges (pinholes) are studied theoretically. We find, at weak magnetic field, a non-zero Hall transresistance. In a…
A Bose-Einstein condensate is the ground state of a dilute gas of bosons, such as atoms cooled to temperatures close to absolute zero. With much smaller mass, excitons (bound electron-hole pairs) are expected to condense at significantly…
We develop a theory for frictional drag between two 2D hole layers in a dilute bilayer GaAs hole system, including effects of hole-hole and hole-phonon interactions. Our calculations suggest significant enhancement of hole drag…
We present a general theory of drag on a condensate due to interactions with a moving thermal bath of non-condensate particles, adapted from previous theory of equilibration of a condensate in a trap. This theory can be used to model the…
Double layer systems where one layer has electrons and the holes are in a parallel layer a distance d away are expected to undergo excitonic condensation at low temperature. This excitonic condensate is traditionally described by a…
The superfluid phase and Coulomb drag effect caused by the pairing in the system of spatially separated electrons and holes in two coaxial cylindrical nanotubes are predicted. It is found that the drag resistance as a function of…
We investigate transport and Coulomb drag properties of semiconductor-based electron-hole bilayer systems. Our calculations are motivated by recent experiments in undoped electron-hole bilayer structures based on GaAs-AlGaAs gated double…
Excitonic insulators (EIs), arising in semiconductors when the electron-hole binding energy exceeds the band gap, are a solid-state prototype for bosonic phases of matter. Unlike the charged excitations that are frozen and unable to…
Bilayer electron-hole systems, where the electrons and holes are created via doping and confined to separate layers, undergo excitonic condensation when the distance between the layers is smaller than typical distance between particles…
Excitons are electron-hole (e-h) pair quasiparticles, which may form a Bose-Einstein condensate (BEC) and collapse into the phase coherent state at low temperature. However, because of ephemeral strength of pairing, a clear evidence for BEC…