Patent ID: 6728281
Filing Date: 2004-04-27
Classification: B82Y,G06N,H01L,H04L,Y10S

Abstract:
A method for producing a single pair of photons with opposite circular polarizations comprising:a) providing a quantum dot embedded in a tunneling structure, wherein the quantum dot has discrete electron energy levels; and wherein the resonant tunneling structure comprises an electron hole reservoir region, an electron reservoir region, and tunnel barrier regions separating the quantum dot from the electron hole reservoir and from the electron reservoir region; b) coupling said quantum dot into an optical cavity; c) applying an electron bias voltage Ve to said tunneling structure producing a resonant electron tunneling condition between the electron reservoir region and said quantum dot such that two electrons with opposite spins tunnel through said tunneling structure into a lowest electron energy level of said quantum dot; and d) applying a hole bias voltage Vh to said tunneling structure to produce a resonant hole tunneling condition between the electron hole reservoir and said quantum dot such that two holes with opposite spins tunnel through said tunneling structure into a lowest hole energy level of said quantum dot and recombine with said electrons to emit said single pair of photons with opposite circular polarizations; wherein said emitted photons are directed into one direction by said optical cavity.