Related papers: Atomic Clocks and Coherent Population Trapping: Ex…
Atomic clocks use atomic transitions as frequency references. The susceptibility of the atomic transition to external fields limits clock stability and introduces systematic frequency shifts. Here, we propose to realize an atomic clock that…
We propose a simple method for measuring the populations and the relative phase in a coherent superposition of two atomic states. The method is based on coupling the two states to a third common (excited) state by means of two laser pulses,…
We discuss the differences between two well-studied and related phenomena---coherent population trapping (CPT) and electromagnetically induced transparency (EIT). Many differences between the two---such as the effect of power in the beams,…
We demonstrate programmable control over the spatial distribution of ultra-cold atoms confined in an optical lattice. The control is facilitated through a combination of spatial manipulation of the magneto-optical trap and atomic population…
Coherent population trapping (CPT) provides a highly sensitive means for probing the energy level structure of an atomic system. For a nitrogen vacancy center in diamond, the CPT offers an alternative to the standard optically-detected…
Active atomic clocks are predicted to provide far better short-term stability and robustness against thermal fluctuations than typical feedback-based optical atomic clocks. However, continuous laser operation using an ensemble of clock…
Ultra-cold atoms trapped in an optical dipole trap and prepared in a coherent superposition of their hyperfine ground states, decohere as they interact with their environment. We demonstrate than the loss in coherence in an "echo"…
Clock-comparison experiments are among the sharpest existing tests of Lorentz symmetry in matter. We characterize signals in these experiments arising from modifications to electron or nucleon propagators and involving Lorentz- and…
A suitable scheme to continuously create inversion on an optical clock transition with negligible perturbation is a key missing ingredient required to build an active optical atomic clock. Re- pumping of the atoms on the narrow transition…
We demonstrate an atom localization scheme based on monitoring of the atomic coherences. We consider atomic transitions in a Lambda configuration where the control field is a standing wave field. The probe field and the control field…
We show that the sensitivity of an atomic clock can be enhanced below the shot-noise level by initially squeezing, and then measuring in output, the population of a single atomic level. This can simplify current experimental protocols which…
We observe bimodal fluorescence patterns from atoms in a fast atomic beam when the laser excitation occurs in the presence of a magnetic field and the atoms sample only a portion of the laser profile. The behavior is well explained by…
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…
Electromagnetically induced transparency (EIT) is an optical phenomenon which allows a drastic modification of the optical properties of an atomic system by applying a control field. It has been largely studied in the last decades and…
We experimentally demonstrate how coherent population trapping (CPT) for donor-bound electron spins in GaAs results in autonomous feedback that prepares stabilized states for the spin polarization of nuclei around the electrons. CPT was…
Creating stable superposed states of matter is one of the most intriguing aspects of quantum physics, leading to a variety of counter-intuitive scenarios along with a possibility of restructuring the way we understand, process and…
We present theoretical and experimental results of coherent population trapping spectra on a multi-level $^{40}$Ca$^+$-type configuration, adding a third beam to the standard two-laser $\Lambda$ system to avoid undesired optical pumping. We…
Currently, the most accurate and stable clocks use optical interrogation of either a single ion or an ensemble of neutral atoms confined in an optical lattice. Here, we demonstrate a new optical clock system based on an array of…
We report the coherent manipulation of internal states of neutral atoms in a magnetic microchip trap. Coherence lifetimes exceeding 1 s are observed with atoms at distances of $5-130 \mu$m from the microchip surface. The coherence lifetime…
Recently, several theoretical proposals adressed the generation of an active optical frequency standard based on atomic ensembles trapped in an optical lattice potential inside an optical resonator. Using atoms with a narrow linewidth…