Dynamic hole blockade yields two-color quantum and classical light from dot-in-bulk nanocrystals

Area of Science:

• Materials Science
• Quantum Optics
• Nanotechnology

Background:

• Semiconductor nanocrystals (NCs) are promising single-photon sources.
• Photon antibunching in NCs typically relies on suppressing multiphoton emission via Auger recombination.

Purpose of the Study:

• To demonstrate a novel antibunching mechanism, dynamic Coulomb blockade, in NCs.
• To enable simultaneous quantum and classical light emission from a single NC without Auger decay.

Main Methods:

• Fabrication of novel dot-in-bulk (DiB) nanostructures with a CdSe core and CdS shell.
• Utilizing the unique electronic properties of DiB structures to control carrier recombination.

Main Results:

• Demonstrated dynamic Coulomb blockade in CdSe/CdS DiB NCs.
• Achieved color-tunable emission: antibunched red light (core) under weak excitation and Poissonian green light (shell) at higher excitation.
• Observed mutually correlated quantum and classical emission channels from the same NC.

Conclusions:

• DiB NCs offer a versatile platform for generating both quantum and classical light.
• The dynamic Coulomb blockade mechanism bypasses Auger recombination limitations.
• These novel nanoscale light sources have potential applications in quantum optics, sensing, and imaging.