Quantum Optomechanics: From Fundamental Tests to Quantum Tools of the Future

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

This award supports research in relativity and relativistic astrophysics and it addresses the priority areas of NSF's "Windows on the Universe" Big Idea. Quantum mechanics was invented to study the behavior of physical systems at the atomic scale. In the past century, understanding the quantum foundations of nature has led to fundamental understanding of the subatomic world, as well as a rich landscape of quantum-enabled technologies, from lasers to magnetic resonance imaging to nanomedicine. The proposed work builds on advances in nanotechnology and precision measurement to push the frontier of both understanding the fundamental nature of the universes, as well as development of quantum sensing technologies for precision measurement. By using the radiation pressure force from intense laser beams to push on mirrors, the exquisite quantum properties of the light can be imprinted onto the mechanical motion of the mirrors. The light itself, in turn, is used to read out the position of the mirror. This light-mirror coupling can be used to generate interesting and practically useful quantum states, provided the thermally driven motion of the mirror is small enough. The proposed work couples laser light to a novel custom-designed macroscopic mirror that has low thermal noise. One goal of the proposed work is to optically trap and cool a macroscopic mirror. This would allow scientists to ask the intriguing question: is there a size scale on which quantum mechanics no longer works? Even though quantum mechanics usually applies to the microscopic world, why would nature have a special size scale? A second, more practical, goal is to use the light-mirror interactions to create an exotic quantum state of light called a "squeezed state.” Squeezed states of light are used to increase the precision of optical measurements, such as the laser interferometry used by LIGO to detect gravitational waves. Squeezed states generated using light-mirror coupling could be well-suited for improving the sensitivity of future gravitational-wave detectors. A notable feature of the proposed work is that it is carried out at room temperature, without the substantial infrastructure and cost of cryogenic cooling, making these devices better suited for enhancing the sensitivity of quantum sensors in a wide range of applications from gravitational-wave detection to quantum information technologies. This work is inherently cross-disciplinary, combining the techniques and formalism of quantum optics, optomechanics, and quantum measurement science with gravitational-wave detection. It therefore advances multiple fields, training personnel with a broad range of skills that prepares them to be part of a technical workforce with quantum expertise, which is increasingly sought after in academia, the government and the private sector. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.