Atomic magnetometry with bandwidth-mismatched NOON states and spectrally-resolved single-photon detection

Project Leader: Michał Lipka , MSc Project period: 2022 - 2025
Project funding: PRELUDIUM 20, NCN
Project description:

The aim of this project is to explore the interaction of broadband quantum light with atomic vapor in the presence of magnetic field, aided with novel technological possibilities brought by ultra-fast cameras able to observe single photons. Previous studies showed that certain kinds of quantum light – light exhibiting properties that cannot be described with classical physics – with a single color (narrowband) can interact with alkali atoms trapped as a vapor in a small glass cell, in a way that let us learn very precisely the magnitude of the magnetic field in the
cell – perform the task of magnetometry. Quantum properties of this faint light let us estimate – reconstruct from measurement data – the magnetic field with precision higher than any classical light (such as produced with a laser or a bulb) would allow. This is often known as surpassing the Standard Quantum Limit (SQL). In the proposed project we will experimentally and theoretically investigate whether using multicolor (broadband) quantum light and separating each color with a diffraction grating (analogous to a prism splitting white light into the rainbow of colors) only before the detection with a single-photon camera would allow to better sense the magnetic field or provide a more experimentally robust setup. We expect the project to deepen the understanding of how broadband quantum light interacts with atomic vapor, especially in the context of atomic sensing (including magnetometry). The technological capabilities to perform such a study only recently became available, and we envisage both fundamentally new insights at the borderline of quantum optics, atomic molecular and optical physics, estimation theory and ultra-fast phenomena, as well as unveiling new prominent applications.

Quantum Optical Devices Lab (QODL)