相关论文: Modulation induced frequency shifts in a CPT-based…

Phase noise of the frequency synthesizer is one of the main limitations to the short-term stability of microwave atomic clocks. In this work, we demonstrated a low-noise, simple-architecture microwave frequency synthesizer for a coherent…

Space-based experiments offer sensitivity to numerous unmeasured effects involving Lorentz and CPT violation. We provide a classification of clock sensitivities and present explicit expressions for time variations arising in such…

We study phase-dependent fluctuations of the resonance fluorescence of a single $\Lambda$-type three-level atom in the regime near coherent population trapping, i.e., alongside the two-photon detuning condition. To this end, we employ the…

We propose an efficient method for demodulation of phase modulated signals via iterated Hilbert transform embeddings. We show that while a usual approach based on one application of the Hilbert transform provides only an approximation to a…

Constraints from clock-comparison experiments on violations of Lorentz and CPT symmetry are investigated in the context of a general Lorentz-violating extension of the standard model. The experimental signals are shown to depend on the…

Atomic response to a probe beam can be tailored, by creating coherences between atomic levels with help of another beam. Changing parameters of the control beam will change the nature of coherences and hence the nature of atomic response as…

In trapped-atom clocks, the primary source of decoherence is often the phase noise of the oscillator. For this case, we derive theoretical performance gains by combining several atomic ensembles. For example, M ensembles of N atoms can be…

We observe coherent population trapping (CPT) in a two-electron atom---$^{174}$Yb---using the $\rm {^1S_0,F=0} \rightarrow {^3P_1,F'=1}$ transition. CPT is not possible for such a transition according to one-electron theory because the…

An automated magnetometer suitable for long lasting measurement under stable and controllable experimental conditions has been implemented. The device is based on Coherent Population Trapping (CPT) produced by a multi-frequency excitation.…

We present a compact atomic clock interrogating ultracold 87Rb magnetically trapped on an atom chip. Very long coherence times sustained by spin self-rephasing allow us to interrogate the atomic transition with 85% contrast at 5 s Ramsey…

We study the possibility of creating a coherent population trapping (CPT) state, involving free atomic and ground molecular condensates, during the process of associating atomic condensate into molecular condensate. We generalize the…

We report an experimental study of an all-optical three-photon-absorption resonance (known as a "N-resonance") and discuss its potential application as an alternative to atomic clocks based on coherent population trapping (CPT). We present…

Atomic magnetometers have very high absolute precision and sensitivity to magnetic fields but suffer from a fundamental problem: the vectorial or tensorial interaction of light with atoms leads to "dead zones", certain orientations of…

Chip-scale microwave atomic systems based on thermal atomic beams offer a promising approach to realize low-power and low-drift clocks for timing holdover applications. Miniature beam clocks are expected to suppress many of the shifts that…

We designed an FPGA fabric to provide phase modulation techniques to lock lasers to optical frequency references. The method incorporates an active residual-amplitude-modulation (RAM) suppression scheme that relies on complex modulation.…

Tests of CPT and Lorentz symmetry using neutral-meson oscillations are studied within a formalism that allows for indirect CPT and T violation of arbitrary size and is independent of phase conventions. The analysis is particularly…

Atom interferometers with long baselines are envisioned to complement the ongoing search for dark matter. They rely on atomic manipulation based on internal (clock) transitions or state-preserving atomic diffraction. Principally, dark…

We propose a compact atomic clock based on ultracold Rb atoms that are magnetically trapped near the surface of an atom microchip. An interrogation scheme that combines electromagnetically-induced transparency (EIT) with Ramsey's method of…

Differential light shifts (DLS) induced by optical trapping fields fundamentally limit the stability and accuracy of trapped-atom microwave clocks. We demonstrate an in-situ method to cancel DLS by simultaneously interrogating multiple…

We introduce a scheme to coherently suppress second-rank tensor frequency shifts in atomic clocks, relying on the continuous rotation of an external magnetic field during the free atomic state evolution in a Ramsey sequence. The method…