Minghui Xu
National Institute of Standards and Technology
Synchronization (computer science)SupercoolingPhysicsCrossoverQuantum decoherencePolaritonQuantum fluctuationLaser linewidthAttosecondIonExtreme ultravioletElectronPhotonQuantum simulatorDipoleUltrashort pulseAtomic physicsOptical cavityScatteringMaterials scienceAtomic clockIonizationCondensed matter physicsCoupling (physics)MoleculeStreakingSteady stateSuperradianceHomonuclear moleculeLasing thresholdNoise (electronics)OptoelectronicsLaserClassical limitMomentumQuantum mechanicsRydberg formulaClassical mechanicsQuantum
Publications 21
#1Simon B. JägerH-Index: 8
#2Minghui XuH-Index: 8
Last. Giovanna MorigiH-Index: 34
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We analyse the dynamics leading to radiative cooling of an atomic ensemble confined inside an optical cavity when the atomic dipolar transitions are incoherently pumped and can synchronize. Our study is performed in the semiclassical regime and assumes that cavity decay is the largest rate in the system dynamics. We identify three regimes characterising the cooling. At first hot atoms are individually cooled by the cavity friction forces. After this stage, the atoms' center-of-mass motion is fur...
13 CitationsSource
#1David TieriH-Index: 9
#2Minghui XuH-Index: 8
Last. Murray HollandH-Index: 46
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Lasing and steady state superradiance are two phenomena that may appear at first glance to be distinct. In a laser, phase information is maintained by a macroscopic intracavity light field, and the robustness of this phase is what leads to the coherence of the output light. In contrast, the coherence of steady-state superradiant systems derives from the macroscopic collective dipole of a many-atom ensemble. In this paper, we develop a quantum theory that connects smoothly between these two extre...
6 Citations
#1Zhe-Xuan GongH-Index: 22
#2Minghui XuH-Index: 8
Last. Alexey V. GorshkovH-Index: 54
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A steady-state superradiant laser can be used to generate ultranarrow-linewidth light, and thus has important applications in the fields of quantum information and precision metrology. However, the light produced by such a laser is still essentially classical. Here, we show that the introduction of a Rydberg medium into a cavity containing atoms with a narrow optical transition can lead to the steady-state superradiant emission of ultranarrow-linewidth nonclassicallight. The cavity nonlineari...
4 Citations
#1Minghui XuH-Index: 8
#2Simon J "agerH-Index: 1
Last. Murray HollandH-Index: 46
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1 Citations
#1Minghui Xu (CU: University of Colorado Boulder)H-Index: 8
#2Simon B. Jäger (Saarland University)H-Index: 8
Last. Murray Holland (CU: University of Colorado Boulder)H-Index: 46
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We investigate laser cooling of an ensemble of atoms in an optical cavity. We demonstrate that when atomic dipoles are synchronized in the regime of steady-state superradiance, the motion of the atoms may be subject to a giant frictional force leading to potentially very low temperatures. The ultimate temperature limits are determined by a modified atomic linewidth, which can be orders of magnitude smaller than the cavity linewidth. The cooling rate is enhanced by the superradiant emission into ...
27 CitationsSource
#1Bihui Zhu (CU: University of Colorado Boulder)H-Index: 13
#2Johannes Schachenmayer (CU: University of Colorado Boulder)H-Index: 20
Last. Ana Maria Rey (CU: University of Colorado Boulder)H-Index: 62
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Macroscopic ensembles of radiating dipoles are ubiquitous in the physical and natural sciences. In the classical limit the dipoles can be described as damped-driven oscillators, which are able to spontaneously synchronize and collectively lock their phases in the presence of nonlinear coupling. Here we investigate the corresponding phenomenon with arrays of quantized two-level systems coupled via long-range and anisotropic dipolar interactions. Our calculations demonstrate that by incoherently d...
57 CitationsSource
#1Minghui Xu (NIST: National Institute of Standards and Technology)H-Index: 8
#2Murray Holland (NIST: National Institute of Standards and Technology)H-Index: 46
We investigate Ramsey spectroscopy performed on a synchronized ensemble of two-level atoms. The synchronization is induced by the collective coupling of the atoms to a heavily damped mode of an optical cavity. We show that, in principle, with this synchronized system it is possible to observe Ramsey fringes indefinitely, even in the presence of spontaneous emission and other sources of individual-atom dephasing. This could have important consequences for atomic clocks and a wide range of precisi...
29 CitationsSource
#1Minghui Xu (NIST: National Institute of Standards and Technology)H-Index: 8
#2David Tieri (NIST: National Institute of Standards and Technology)H-Index: 9
Last. Murray Holland (NIST: National Institute of Standards and Technology)H-Index: 46
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We propose a system for observing the correlated phase dynamics of two mesoscopic ensembles of atoms through their collective coupling to an optical cavity. We find a dynamical quantum phase transition induced by pump noise and cavity output coupling. The spectral properties of the superradiant light emitted from the cavity show that at a critical pump rate the system undergoes a transition from the behavior of two independent oscillators to the phase locking that is the signature of quantum syn...
123 CitationsSource
#1Peiru HeH-Index: 3
#2Minghui XuH-Index: 8
Last. Murray HollandH-Index: 46
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