Breaking boundaries in quantum photonics: New nanocavities unlock new frontiers in light confinement

Phys.org  February 5, 2024 Confinement of light into nanocavities which enhances light–matter interactions generally come at the cost of absorption and low resonator quality factors. An international team of researchers (Israel, USA – Cornell University, Kansas State University, Germany, Spain) suggested an alternative optical multimodal confinement mechanism, unlocking the potential of hyperbolic phonon polaritons in isotopically pure hexagonal boron nitride. They produced deep-subwavelength cavities and demonstrated several orders of magnitude improvement in confinement approaching the intrinsic quality factor of hexagonal boron nitride polaritons. The quality factors they obtained exceeded the maximum predicted by impedance-mismatch considerations indicating that confinement was boosted […]

Cooling radio waves to their quantum ground state

Phys.org  October 15, 2021 In standard cryogenic systems thermal decoherence prevents access to the quantum regime for photon frequencies below the gigahertz domain. An international team of researchers (the Netherlands, Germany) engineered two superconducting LC circuits coupled by a photon-pressure interaction and demonstrated sideband cooling of a hot radio frequency (RF) circuit using a microwave cavity. Because of a substantially increased coupling strength, they obtained a large single-photon quantum cooperativity and reduced the thermal RF occupancy by 75% with less than one pump photon. For larger pump powers, the coupling rate exceeds the RF thermal decoherence rate by a factor […]

Pristine Quantum Light Source Created at the Edge of Silicon Chip

IEEE Spectrum  October 10, 2018 Researchers at the University of Maryland injected light into a chip containing an array of miniscule silicon loops arranged in a way that always allows the light to travel undisturbed around the edge of the chip, even if fabrication defects are present. The light circulates around each loop thousands of times before moving on to a neighboring loop. The relatively long journey is necessary to get many pairs single photons out of the silicon chip. Their quantum light source reliably produced high quality, single-color photons time and again, whereas the conventional chip’s output was more […]