Within this newly founded project, our aim is to study the fundamental limits of energetic measurements and the information-energy equivalence in nanostructures cooled down to millikelvin temperatures.

A combination of low temperature and miniaturized sensor size often yields the ultimate sensitivity for various detector applications. At temperatures close to the absolute zero (say, in the range from 0.01 to 10 degrees Kelvin), exotic phenomena such as quantization of charge, magnetic flux, and mechanical motion as well as superconductivity and quantum coherence can be exploited in radically new device designs. Conversely, typical challenges in these experiments are related to thermalization, isolation from the environment, and back-action from the measurement circuitry.

Our first priority is constructing a highly sensitive nano-calorimeter platform that measures quanta of energy through an increase in the temperature of the platform. We will make full use of the toolbox of mesoscopic physics to realize the best possible energy resolution. We depart from traditional calorimeter design in the choice of signal to detect. Rather than x-rays, i.e., free space high-energy photons, our absorber will be primarily sensitive to energy in the form of mechanical vibrations.

We envision using the mechanical calorimeter in three ground-breaking experiments. First, the detection (counting) of individual phonons analogously to detection of optical phonons with a photodiode. Second, measurement of the unavoidable production of heat from information-processing circuits in accordance with the Landauer principle and its extensions. And third, development of an analysis tool allowing thermodynamic measurements on individual biomolecules.

This project is in its dynamic early stages. Presently, we are building our measurement capabilities in two laboratories on the Caltech campus. One setup will be dedicated for investigation of fundamental device physics, whereas the other one has "beamline" access ports, allowing particles or bioanalytes to be deposited on the cold detector element.