Pancharatnam–Berry phase in condensate of indirect excitons

  title={Pancharatnam–Berry phase in condensate of indirect excitons},
  author={J R Leonard and Alexander A. High and Aaron Tynes Hammack and Michael M. Fogler and L V Butov and Kenneth Lee Campman and Arthur C. Gossard},
  journal={Nature Communications},
The Pancharatnam–Berry phase is a geometric phase acquired over a cycle of parameters in the Hamiltonian governing the evolution of the system. Here, we report on the observation of the Pancharatnam–Berry phase in a condensate of indirect excitons (IXs) in a GaAs-coupled quantum well structure. The Pancharatnam–Berry phase is directly measured by detecting phase shifts of interference fringes in IX interference patterns. Correlations are found between the phase shifts, polarization pattern of… 

Moiré pattern of interference dislocations in condensate of indirect excitons

It is shown that the observed interference dislocations originate from the moiré effect in combined interference patterns of propagating condensate matter waves, which are formed by the IX matter waves ballistically propagating over macroscopic distances.

Interference dislocations in condensate of indirect excitons

Phase singularities in quantum states play a significant role both in the state properties and in the transition between the states. For instance, a transition to two-dimensional superfluid state is

Dynamical formation of a strongly correlated dark condensate of dipolar excitons

It is shown that a dense Bose–Einstein condensate can be formed in an optically inactive state, previously believed to be unstable, due to short-range exchange interactions between excitons, and it is found that strong dipole–dipole interactions stabilize the dark condensates.

Emergence of the geometric phase from quantum measurement back-action

The state vector representing a quantum system acquires a phase factor following an adiabatic evolution along a closed trajectory in phase space. This is the traditional example of a geometric phase,

Indirect Excitons and Trions in MoSe2/WSe2 van der Waals Heterostructures.

This work presents studies of IXs in MoSe2/WSe2 heterostructures and reports on two IX luminescence lines whose energy splitting and temperature dependence identify them as neutral and charged IXs, and the experimentally found binding energy of the indirect charged excitons is close to the calculated binding energy for negative indirect trions in TMD heterostructure.

Excitons and emergent quantum phenomena in stacked 2D semiconductors.

Outstanding challenges in the field are identified and a roadmap for unlocking the full potential of excitonic physics in TMD double layers and beyond is presented, such as incorporating newly discovered ferroelectric and magnetic materials to engineer symmetries and add a new level of control to these remarkable engineered materials.

Localized bright luminescence of indirect excitons and trions in MoSe$_2$/WSe$_2$ van der Waals heterostructure

Indirect excitons (IX) in semiconductor heterostructures are bosons, which can cool below the temperature of quantum degeneracy and can be effectively controlled by voltage and light. IX quantum Bose

Moiré Pattern of Interference Dislocations and Superfluidity in Condensate of Indirect Excitons

We present a new mechanism, the moiré effect, which leads to the appearance of dislocations in interference patterns. Remote interference dislocations in condensate of indirect excitons originate

High-mobility indirect excitons in wide single quantum well

Indirect excitons (IXs) are bound pairs of electrons and holes confined in spatially separated layers. We present wide single quantum well (WSQW) heterostructures with high IX mobility, spectrally

Condensation of indirect excitons

<jats:p><jats:fig position="anchor"><jats:graphic xmlns:xlink="" mime-subtype="png" mimetype="image" position="float" xlink:href="S0883769420001232_figAb.png"



Unconventional Bose—Einstein Condensations from Spin-Orbit Coupling

According to the “no-node" theorem, the many-body ground state wavefunctions of conventional Bose—Einstein condensations (BEC) are positive-definite, thus time-reversal symmetry cannot be

Spontaneous coherence in a cold exciton gas

It is found that spontaneous coherence of excitons emerges in the region of the macroscopically ordered exciton state and in the area of vortices of linear polarization, indicating a coherent state with a much narrower than classical exciton distribution in momentum space, characteristic of a condensate.

Observation of the optical spin Hall effect

The spin Hall effect consists of the generation of a spin current perpendicular to the charge current flow. Thirty-five years after its prediction by Dyakonov and Perel'1, it is the focus of

Ballistic spin transport in exciton gases

Traditional spintronics relies on spin transport by charge carriers, such as electrons in semiconductor crystals. The challenges for the realization of long-range electron spin transport include

Effect of spatial resolution on the estimates of the coherence length of excitons in quantum wells

We evaluate the effect of diffraction-limited resolution of the optical system on the estimates of the coherence length of two-dimensional excitons deduced from the interferometric study of the

Quantal phase factors accompanying adiabatic changes

  • M. Berry
  • Physics
    Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences
  • 1984
A quantal system in an eigenstate, slowly transported round a circuit C by varying parameters R in its Hamiltonian Ĥ(R), will acquire a geometrical phase factor exp{iγ(C)} in addition to the familiar

Exciton spin dynamics in quantum wells.

Analysis of the time dependence of optical intensities of both circular polarizations, including competing relaxation mechanics from exciton exchange and from single-particle spin flip into optically inactive states, leads to characteristic shapes reflecting their relative importance.

Polariton spin whirls

We report on the observation of spin whirls in a radially expanding polariton condensate formed under nonresonant optical excitation. Real space imaging of polarization- and time-resolved

Stimulated scattering of indirect excitons in coupled quantum wells: signature of a degenerate Bose-gas of excitons.

A strong enhancement of the exciton scattering rate to the low-energy states with increasing concentration of the indirect excitons is observed and bosonic stimulation ofexciton scattering is revealed, which is a signature of a degenerate Bose-gas of exciteons.

Spin currents in a coherent exciton gas.

The observed long-range spin currents originate from the formation of a coherent gas of bosonic pairs--a new mechanism to suppress the spin relaxation, and control of the spin currents by a magnetic field is demonstrated.