GOALI: Tunable Quantum Coupling in Nanomechanical Heterostructures

NSF 0702515

GOALI: Tunable Quantum Coupling using Nanomechanical Heterostructures

Objective:

The objective of this research is to determine whether the energy levels of surface quantum wells can be tuned using nanomechanical actuation like the resonant frequency of an optical cavity can be tuned using movable mirrors. Both interband and intersubband level transitions will be investigated. The approach is to utilize micromachined cantilevers of compound semiconductor heterostructures that have collapsed across a nanometer-scale gap. Such devices are easy to fabricate and naturally collapse upon etch release. Further, the gap height gradually changes from gap to contact making light emission studies versus quantum coupling much easier.

Intellectual Merit:

The merits of such an approach are significant. New physics is involved, and the amount of energy state tuning that can be achieved is immense compared to current technology. Theoretical analysis shows that two surface quantum wells brought into contact could shift their first quantized levels by over 150nm, limited ultimately by band offsets at high energies and thermal broadening at low energies.

Broader Impact:

The impact of the research could be immense. Current semiconductor light emitters and detectors have limited tuning ranges. The concepts here could extend the tuning of interband transitions to 30% and intersubband transitions to an order of magnitude. This program will provide opportunities for undergraduate researchers as part of a Nanotechnology Network initiative for women, minorities, and students from small colleges. The program will also include research opportunities for one or more high school students through a Mentor Program in one of the local school districts of the Twin Cities area.

Word Count: 248 Words (not including section titles)