ECE News Story
Naik is Lead Author of Nature Journal Article on Quantum Back-Action
Recent Ph.D. graduate Akshay Naik was part of a University of Maryland research team led by Dr. Keith Schwab whose work was recently published in the journal Nature. Naik, along with Dr. Olivier Buu of the Laboratory for Physical Sciences and Department of Physics, were the lead authors of the article, titled "Cooling a nanomechanical resonator with quantum back-action."
The paper documents the group's use of superconducting single electron transistor (SSET) to detect the motion of a nanomechanical resonator that is close to its quantum ground state. The question the research team attempted to answer was: How close does this transistor get to the limits posed by quantum mechanics? One of the fundamental limits in the detection of the position is the back-action of the SSET. The process of detection itself disturbs the motion of the nanomechanical resonator. The group took the last two to three years to find out how this back-action of SSET affects the resonator.
The group discovered that it is possible to heat or cool the nanomechanical resonator just by changing the bias conditions of the SSET.
"The fact that it is possible to cool something just by coupling it to a noisy detector is counterintuitive," said Naik. "Although the cooling power of this refrigerator is very small, it should be possible to produce ultra-cold quantum states in a sufficiently isolated mechanical resonator."
The group was also able to show that their detector is just 15 times away from the uncertainty principle requirements for a detector. Their work also has implications for quantum information processing and ultra sensitive force microscopy.
September 18, 2006