Superconducting Circuits and Quantum Electromechanical Systems
Research in the LaHaye group focuses on the development of new technology to explore quantum mechanical behavior in the motion of engineered systems. While quantum mechanics was initially developed to account for the physical behavior of systems at the atomic scale, experiments over the past century have shown it to be applicable to a larger and larger domain of systems, stretching from the constituents of atomic nuclei to superconducting circuits and microwave cavities. In fact, in just the past several years, researchers have begun to observe signatures of the quantum realm in the motion of nano- and micro-fabricated structures that have been carefully engineered and measured under very stringent conditions (i.e. at temperatures of only a few hundredths of a degree above absolute zero). While these quantum electromechanical systems are microscopic in size, they still consist of billions of atoms and thus represent the largest systems to date for which quantum signatures of motion have been observed.
How far up in size-scale the applicability of quantum mechanics may extend remains an open question. But these systems, and larger ones being developed by researchers in the community, offer new prospects for investigating how the classical world (the world of our everyday experience) emerges from the quantum world and the potential to explore new physics in complex systems at the interface between these two worlds. In the process of pursuing these fundamental questions, the field is developing novel and exquisitely sensitive electromechanical (and optomechanical) technologies that have an array of applications ranging from quantum computation and information processing to materials imaging and sensing of weak signals to the details of energy transport and dissipation in materials.
For a fairly recent and non-technical review of the field see the following link: http://authors.library.caltech.edu/32352/1/PTO000029.pdf.
For a technical discussion of the LaHaye group’s efforts in recent years to integrate superconducting circuitry with nanomechanical systems for the development of new quantum electromechanical systems, see http://arxiv.org/abs/1504.02908.