From Single Quanta to Macro Coherence

Quantum mechanics is the language in the microscopic world where single or few particles and quasi-particles are fully described by their complex wavefunctions and a Hermitian system Hamiltonian. When the number of particles grows large, phase correlation among the particles is lost due to interaction with the environment — and we enter the classical world of human scales. In some special systems, however, phase correlations survive among a macroscopic number of particles over macroscopic distances, and remarkable collective quantum phenomena emerge. Those are the systems that we study.

Earlier examples of such studies have led to tremendous advances in modern science and technology, such as stimulated scattering and lasers, Bardeen-Cooper-Schrieffer state and superconductors, Bose-Einstein Condensation and precision measurement. Our current interest centers on the discovery, creation, control and applications of both single quantum state and collective quantum phenomena in solid and light systems.


New Regimes of Light-Matter Coupling in Two-Dimensional Materials

An interlayer exciton laser from a bi-molecular layer heterostructure

An interlayer exciton laser
[Image credit: Larrea Young,]

  • Fundamental optical, electrooptical, excitonic and polaritonic properties of van der Waals materials.
  • Regimes of coherent light-matter interactions and cooperative phenomena in van der Waals semiconductors.
  • MoirĂ© physics in two-dimensional heterostructures.
  • Ultra-low energies photonics with van der Waals semiconductors.
  • Novel structures and measurement techniques for two-dimensional material systems.

More information about 2D materials polariton MURI project is available here.



Collective Quantum States of Matter and Light in Open Systems

A Polariton Laser in a monolithic designable microcavity

A Polariton Laser

  • Strong-coupling phenomena in novel structures and materials
  • Collective phenomena in light and matter coupled systems, including quantum nonlinear dynamics, non-equilibrium phase transitions, non-Hermitian  of many-body systems.
  • Low-dimensional and coupled quantum gasses of polaritons.
  • Controlling light-matter interactions and fundamental properties of the light-matter coupled modes using designer photonic structures


More information on GaAs polariton systems in posters:

A designer GaAs polariton system.

The Bardeen-Cooper-Schrieffer regime of polaritons.

Frequency bifurcation at limit cycle in dissipatively coupled polariton condensates.


Earlier projects:

Quantum Photonics & Plasmonics with Wide Bandgap Materials


(Left) Dot Array, (Right) Dot PL.

  • Site-controlled (In)GaN nanostructures and quantum dots.
  • High temperature single photon source.
  • Plasmon and quantum dot coupling.
  • Single- and few-emitter QED.

A poster about this project is available here.


Optical Vortices


(Top) Vortex Images, (Bottom) Zeno Sorter.

A poster about this project is available here.

  • Generation and propagation of high purity optical vortices.
  • High fidelity, compact optical vortex sorters.
  • High-dimensional quantum information processing with optical vortices.