arXiv subjects

Yu-Zhu Wang

Publications and source records attributed to Yu-Zhu Wang.

6 recordsLinked to original sources

arXiv2022

Estimating gravity acceleration from static atomic gravimeter by Kalman filtering

We present the construction of the two-state model of the atomic gravimeter and the associated Kalman recursion to estimate gravity acceleration from atomic gravimeter. We find the Kalman estimator greatly improve the precision of estimates in short term by removing the white phase noise. The residual noise of the estimates follows 0.13 muGal/\sqrt{s} for up to more than 100 s and highlights a precision of 0.34 muGal at the measuring time of a single sample, even with no seismometer correction.

physics.atom-ph↗

arXiv2015

Cyclotron Dynamics of a Kondo Singlet in a Spin-Orbit-Coupled Alkaline-Earth Atomic Gas

We propose a scheme to investigate the interplay between Kondo-exchange interaction and quantum spin Hall effect with ultracold fermionic alkaline-earth atoms trapped in two-dimensional optical lattices using ultracold collision and laser-assisted tunneling. In the strong Kondo-coupling regime, though the loop trajectory of the mobile atom disappears, collective dynamics of an atom pair in two clock states can exhibit an unexpected spin-dependent cyclotron orbit in a plaquette, realizing the quantum spin Hall effect of the Kondo singlet. We demonstrate that the collective cyclotron dynamics of the spin-zero Kondo singlet is governed by an effective Harper-Hofstadter model in addition to second-order diagonal tunneling.

cond-mat.quant-gas↗

arXiv2014

Interacting heavy fermions in a disordered optical lattice

We have theoretically studied the effect of disorder on ultracold alkaline-earth atoms governed by the Kondo lattice model in an optical lattice via simplified double-well model and hybridization mean-field theory. Disorder-induced narrowing and even complete closure of hybridization gap have been predicted and the compressibility of the system has also been investigated for metallic and Kondo insulator phases in the presence of the disordered potential. To make connection to the experimental situation, we have numerically solved the disordered Kondo lattice model with an external harmonic trap and shown both the melting of Kondo insulator plateau and an compressibility anomaly at low-density.

cond-mat.quant-gas↗

arXiv2010

Life-span of classical solutions to hyperbolic geometric flow in two space variables with slow decay initial data

In this paper we investigate the life-span of classical solutions to the hyperbolic geometric flow in two space variables with slow decay initial data. By establishing some new estimates on the solutions of linear wave equations in two space variables, we give a lower bound of the life-span of classical solutions to the hyperbolic geometric flow with asymptotic flat initial Riemann surfaces.

math.DG↗

arXiv2009

Enhanced cooling of rubidium atoms in two-frequency diffuse lights

In this paper we describe an experiment of efficient cooling of $^{87}$Rb atoms in two-frequency diffuse laser lights. Compared with single frequency diffuse light, two-frequency diffuse lights have wider velocity capture range and thus can cool more atoms. In our experiment, the maximum number of cooled atoms can reach up to $3.9\times10^9$. Such a result is quite useful in building a compact cold atom clock.

physics.atom-ph↗

arXiv2001

Fragmented Condensate Ground State of Trapped Weakly Interacting Bosons in Two Dimensions

The ground state and its structure for a rotating, harmonically trapped N-Boson system with a weak repulsive contact interaction are studied as the angular momentum L increases up to 3N. We show that the ground state is generally a fragmented condensate due to angular momentum conservation. In response to an (arbitrarily weak) asymmetric perturbation of the trap, however, the fragmented ground state can be transformed into a single condensate state. We manifest this intrinsic instability by calculating the conditional probability distributions, which show patterns analogous to the boson density distributions predicted by mean-field theory.

cond-mat.stat-mech↗