| INTRODUCTION | WHAT's NEW |
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We study the physical foundation of future information technologies, namely, how to produce, protect, process, and probe coherence of quantum systems, such as spins in solid-state materials, with potential applications in quantum sensing, quantum computing, optical communications, and spintronics. The specific physical systems under consideration include semiconductor quantum dots, defects in solids (nitrogen-vacancy centers in diamond, donors in silicon, radicals in organic crystals, etc.), topological insulators, and cold atoms in optical fields. |
9 Feb 2022. Physical Review Research published our scheme of zero-field magnetometry
16 Dec 2021. R. B. Liu is listed as a recipient of the Willis E. Lamb Award
4 Nov 2021. R. B. Liu is elected as a Fellow of Optica
31 Aug 2021. Dr. Dawu Xiao joins our group
2 Aug 2021. Physical Review A published our study on effects of decoherence on quantum critical metrology
13 Jul 2021. Internal geometry of Majorana constellation and Berry phases of spin-1 [New J Phys]
13 Apr 2021 Tracking of nanodiamond's rotation in cells [Nano Letters]
22 Nov 2020 Quantum sensing can not only enhance exisiting metrology technology, but also enable new ones that have no classical counterparts [Express Letter of Chinese Physics Letters] [PDF]
13 Mar 2020 Physical Review A publishes our study on the Majorana representation of three-qubit tangle
2 Aug 2019 New Journal of Physics publishes our discovery that there is no singular sensitivity enhancement at the excitional point of a non-Hermitian system
1 Aug 2019 Physical Review Letters publishes our paper "Characterization of Arbitrary-Order Correlations in Quantum Baths by Weak Measurement"
22 Jul 2019 Nature Communications publishes our paper "Nanometer-precision non-local deformation reconstruction using nanodiamond sensing"
22 Mar 2019 Nature Communications publishes our work on quantum control of nitrogen-vacancy spins at temperature near 1000 K
05 Feb 2019 Nature Communications publishes our paper "High-resolution spectroscopy of single nuclear spins via sequential weak measurements"
09 Aug 2018 Nature Communications publishes our paper "Hybrid nanodiamond quantum sensors enabled by volume phase transitions of hydrogels"
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RESEARCH HIGHLIGHTS
 Cover Story - topological quantum optics. Atoms coupled to different optical fields form a Superradiance Lattice in momentum space (PRL 2015). Under three lights periodically modulated with different phases, the SL simulates the famous Haldane model for 2D topological insulators (Optica 2015). Such lattices can be employed for generation of Schrodinger cat states of photons (PRL 2016). The topological properties of SLs extend topological physics to quantum optics. |
 Central spin decoherence is deeply related to partition function of environment: The coherence zeros correspond to Lee-Yang zeros and a new type of phase transitions - time-domain phase transitions correspond to the singularities in the complex plane of physical parameters. [Phys. Rev. Lett. (2012)] After more than 60 years of their theoretical studies, Lee-Yang zeros now observed [Phys. Rev. Lett. (2015), highlighted in Physics]. |
 Light for trillion-bit rate communication: Following our prediction, we observed up to 11 colors generated from a monochromatic light through a semiconductor irradiated by a strong THz laser [Nature 2012]. The figure is by R. Huber [News & Views, Nature]. Graphene may be a more efficient material for high-order THz sideband generation [Nature Communications 2014] |
 Magnetometry: Spin coherence of a nitrogen-vacancy center in diamond can be used to identify distant nuclear spin pairs and detect NMR of single molecules Nature Nanotech.(2011). The idea has been partially realized by experiments [Nature Nanotech. (2012), Nature Phys. (2014)] |