Manipulating photon emission efficiency with local electronic states in a tunneling gap

Area of Science:

• Surface Science
• Quantum Tunneling
• Plasmonics

Background:

• Photon emission efficiency in tunneling gaps is crucial for nanoscale optoelectronics.
• Controlling electron tunneling processes (elastic and inelastic) is key to manipulating light emission.
• Local electronic states significantly influence quantum phenomena at surfaces.

Purpose of the Study:

• To demonstrate the manipulation of photon emission efficiency in a tunneling gap.
• To investigate the role of artificial local electronic states in controlling photon emission rates.
• To establish tip-induced photon emission as a method for probing electronic states.

Main Methods:

• Utilized a scanning tunneling microscope (STM) tip to create artificial local electronic states on a CuN nanoisland on a Cu(100) surface at cryogenic temperatures.
• Tuned bias voltages to modulate elastic and inelastic electron tunneling rates.
• Developed and applied a theoretical model to analyze tunneling processes and electronic states.

Main Results:

• Demonstrated that local electronic states can enhance or suppress tip-induced surface plasmon modes and photon emission rates.
• Observed a direct correlation between the characteristics of electronic states and photon emission efficiency.
• The theoretical model showed excellent agreement with experimental observations.

Conclusions:

• Photon emission efficiency in tunneling gaps is controllable by manipulating local electronic states and tunneling processes.
• STM-induced photon emission serves as a powerful tool for characterizing electronic states in tunneling junctions.
• This work opens avenues for novel nanoscale light sources and electronic state spectroscopy.