Field of Specialization: Experimental Condensed Matter Physics

Research Interests: Optical Properties of Semiconductor Nanostructures

Hailin Wang’s research interests lie in an area between quantum optics and condensed matter physics.  Two major themes in Wang’s group have been coherence and cavity quantum electrodynamics (QED) in semiconductor nanostructures.
Optical excitation of simple quantum systems can generate a quantum mechanical coherent superposition.  The evolution, interaction, and decay of this optically induced coherence can lead to a wide variety of fascinating physical phenomena.  In semiconductors, coherent optical processes are also strongly influenced by electron-electron and electron-photon interactions, leading to striking differences between optical properties of isolated atoms and semiconductors.  Currently, Wang’s group is investigating the manifestation of coherent optical phenomena, such as Rabi oscillation and electromagnetically-induced transparency, in semiconductors.
A mesoscopic structure where single quantum dots couple strongly to a single mode of electromagnetic field provides a model system for controlling fundamental optical interactions in quantum dots.  In the limit that the dipole-couplings rate between a quantum dot and a resonant cavity mode exceeds relevant decoherence rates, spontaneous emission from the quantum dot, which is usually viewed as an irreversible decay process, becomes reversible.  To realize such systems, Wang’s group is developing a composite microcavity system based on colloidal quantum dots coupling to whispering gallery modes in a fused silica microsphere.  Research efforts also focus on the use of the cavity QED system for creation and manipulation of quantum entanglement of quantum dots.