Wang Group Research

An intriguing aspect of quantum mechanics is that a quantum system can exist in a coherent superposition of different eigenstates of an observable.  This coherent quantum superposition, or simply quantum coherence, plays a central role in many areas of science.  A major theme of Hailin Wang’s research is optical studies of quantum coherences in semiconductor nanostructures.  Using artificially engineered electronic and photonic structures, Wang’s group aims to understand and control quantum coherences in semiconductors.  Research in this area is of great general interest because of the potential to impact next-generation information technologies.

Electron spin coherences are exceptionally robust compared with other forms of quantum coherences in semiconductors and thus provide us a highly promising platform for developing coherent quantum devices.  Currently, Wang’s group uses coherent nonlinear optical techniques to investigate fundamental decoherence processes of electron spins in semiconductors.  Wang’s group also exploits the electron spin coherence to pursue electromagnetically induced transparency, a remarkable phenomenon in which destructive quantum interference induced by the spin coherence renders an otherwise opaque medium transparent.  

Another area of interest in Wang’s group is cavity QED with artificial atoms such as quantum dots and defect centers, in which artificial atoms couple to cavity modes in an optical micro-resonator.  These cavity QED systems can enable the investigation and control of fundamental optical processes at the level of single photons.