In 2012,
Huazhong University of Science and Technology (Wuhan) developed a cold rubidium atom interferometry with vibration isolator with resolution comparable state-of-the-art cold atom gravimeters
Since then, China has been the World leader in cold atom interferometry tech with only two competitors, i.e. America and France.
In the same year,
CNRS/France reported the first operation of an airborne atom interferometer
Huazhong team developed an 87Rb atom interferometer using stimulated Raman transitions. They added a 2D magneto-optical trap to increase the atom number and improve the detection signal-to-noise ratio, and a better optical phase-locked system to reduce the phase noise. Sensitivity of ~ 4.2 μGal/√Hz was reached.
In the same year
Sandia/America broke the record
2014
CNRS/France reported the best sensitivity without any ground based vibration isolation system in an underground expt.
Huazhong achieved sensitivity of 67
μGal/√Hz, they reclaimed the lead.
NIST+PTB (Germany) - Transportable strontium optical clock
2015
Huazhong - Uncertainty of gravity measurements contributed by the single-photon shift corrected
2016
CNRS/France reported highest rotation stability
Huazhong reported the first ever test of the Universality of Free Fall with atoms in different spin orientations,
2017
UC Berkley + Zhejiang demonstrated multi-axis atom interferometry with a single-diode laser that can do all functions like atom trapping, interferometry, and detection. With rotation sensitivity 300
μrad/s/√Hz.
2018
Chinese Academy of Science – World’s first In-orbit operation of an atomic clock based on laser-cooled 87Rb atoms;
Chinese Academy of Science designed a compact portable laser system for cold atom interferometers. The laser system was mounted on a single module, and experiencing 1200-km-long truck transportation.
In the same year, they achieved sensitivity = 230
μGal/√Hz, World’s highest. This time the laser system only contained one 780 nm seed laser, and stimulated beams coupled with pair of cooling beams by using a liquid crystal based polarization control.
National Institute of Metrology (Beijing) also reached sensitivity of 44
μGal/√Hz.
UC Berkeley used atom interferometry with a cloud of cesium atoms to successfully measure quantum electrodynamics.
2019
Zhejiang University and Zhejiang University of Technology achieved sensitivity = 300
μGal/√Hz, World’s highest.
NIST/ University of Colorado - Single-Source Multi-axis Cold-Atom Interferometer in a Centimeter-Scale Cell;
2020
Chinese Academy of Science - External-cavity diode laser (ECDL) for space based strontium optical clock
2021
Huazhong - Car-based portable cold atom interferometry; Sensitivity = 1.9
mGal/√Hz
Huazhong – 3D position of an atomic cloud
;
National University of Defense Technology (Changsha) - Vibration isolation system
2022
Naval University of Engineering (Wuhan) - Underwater based vibration isolation system;
ONERA/France – Moving aircraft/ship based cold atom interferometry;
Huazhong – World’s highest rotation sensitivity = 40 nrad/
√Hz; an improvement on the sensitivity by factor of 32,
paves the way to study the Earth’s crust with a quantum sensor.
Huazhong – Aircraft/ship based cold atom interferometry with first ever vibration noise suppression factor >50.
UC Berkeley (3/6 Chinese) - Aircraft based cold atom interferometry; Sensitivity = 37 Gal/Hz; Sensor payload = 100-150 Kg.
Chinese Academy of Science - Cold atom interferometry with highest level of compactness; sensor volume<100 liter.
SAST+Huazhong+Nanhang – Space-borne Atom-Interferometry; sensitivity of 1.9 mE/Hz1/2 ; accuracy of 0.2 cm@100 km
.
National University of Defense Technology (Changsha) - Estimating the uncertainty of an atom gravimeter;
Large-scale cold atom interferometer –
China – Chines Academy of Science; Wuhan based;
America – Stanford + Johns Hopkins + Fermi Lab + Northwestern + Oxford + Cambridge
France – CNRS -