Synchronized Swimming in a Two-Dimensional Electron Gas

Schematic of electrons, excitons, and trions in a doped semiconductor

Schematic of electrons, excitons, and trions in a doped semiconductor

Electrons tightly confined to a two-dimensional sheet in a semiconductor nanostructure have been demonstrated as an excellent platform for nanoscale devices and quantum information applications; however, interactions between electrons typically hinder device performance by stimulating chaotic behavior.  In this work, published March 7th in Physical Review Letters, we demonstrate that instead of being detrimental, these many-body

Two dimensional coherent spectrum showing peaks due to interaction between excitons and trions

Two dimensional coherent spectrum showing peaks due to interaction between excitons and trions

interactions can synchronize the electrons to act in unison, and this coherent behavior could be exploited for novel quantum devices.  Electronic interactions are studied using optical two-dimensional coherent spectroscopy, a technique that uses a series of ultrafast laser pulses to excite specific electronic transitions in the nanostructure.  The spectral content of the emitted light is analyzed while systematically varying the delays between the excitation pulses, which yields spectral information not accessible using other techniques.  These results provide unique insight into the fundamental nanoscale interactions responsible for the collective behavior of the electronic system.  The coherent many-body signals revealed in this work are comparable in strength to other quantum systems developed for quantum information applications, demonstrating the promise of a two-dimensional electron gas in a semiconductor nanostructure as a new avenue for coherent opto-electronic devices.