Mr. Yohei Nishino from the University of Tokyo

Abstract:

Interferometric gravitational-wave detectors are highly precise displacement sensors, and their sensitivity is fundamentally limited by two forms of quantum noise: shot noise, which limits measurement precision, and radiation pressure noise, which represents the quantum back-action of the measurement. These two noise sources are quantum conjugates, forming a trade-off known as the standard quantum limit (SQL). In this presentation, we introduce two quantum techniques to surpass the SQL: squeezed light injection and quantum non-demolition speed measurement. Both approaches enable sensitivity beyond the SQL, expanding the observational horizon of future gravitational-wave detectors and paving the way for deeper exploration of the universe.

Biography:

Yohei Nishino is a Ph.D. student in the Department of Astronomy at the University of Tokyo. His research focuses on quantum noise reduction techniques for interferometric gravitational-wave detectors from both theoretical and experimental sides, with particular emphasis on the use of quantum entanglement.