Frequency Measurements of Superradiance from the Strontium Clock Transition

Abstract

We present the first characterization of the spectral properties of superradiant light emitted from the ultranarrow, 1-mHz-linewidth optical clock transition in an ensemble of cold 87 Sr atoms. Such a light source has been proposed as a next-generation active atomic frequency reference, with the potential to enable high-precision optical frequency references to be used outside laboratory environments. By comparing the frequency of our superradiant source to that of a state-of-the-art cavity-stabilized laser and optical lattice clock, we observe a fractional Allan deviation of 6.7ð1Þ × 10 −16 at 1 s of averaging, establish absolute accuracy at the 2-Hz (4 × 10 −15 fractional frequency) level, and demonstrate insensitivity to key environmental perturbations.

Monte-Carlo simulations of superradiant lasing

“…The corresponding coherence time is about 16 s and is thus hundred times longer than the time spent by any typical atom in the cavity. The MCWF unraveling of the density matrix may also be applied to extract important insight into dynamical evolution of the quantum states in superradiant beats [22], synchronization [23], and spin-squeezing [24] of atomic ensembles.…”

“…1elements. Notice the atoms can be prepared in a superposition of the fully symmetric Dicke states by driving the cavity mode [22]. If the system is initially prepared in a single Dicke state, e.g.…”

Ultracold polar molecules as qudits

“…We consider ultracold molecules trapped in the motional ground states of optical tweezers. Tweezers are an established tool for atoms [70][71][72][73][74][75], and have recently been extended to ultracold molecules, both by loading laser-cooled molecules directly into tweezers [76] and by associating atoms in a tweezer to form molecules [48,49]. Tweezers offer single-particle addressability and detection, combined with easy scaling up to arrays of ∼100 traps [73][74][75], making them an ideal platform for quantum computation with ultracold molecules.…”

Superradiance from lattice-confined atoms inside hollow core fibre

“…1c). 5 The SR output is coupled to a single-mode fibre (SMF) and mixed with a local oscillator LO ( , ) =̂L O ( ) cos LO by a 50:50 fibre coupler (see Methods). The power and the frequency of local oscillator are on the order of 1 mW and LO = 0 − Ω 0 with Ω 0 = 2 × 50 MHz respectively.…”

“…In addition to its undisputed importance in fundamental science, SR also has substantial applications in various fields. For example, lasing based on SR has been proved to be a potentially outstanding frequency reference because of its strong immunity to 2 environmental perturbations 4,5 . In quantum information, SR is utilized in realizing quantum memories 6,7 and single photon sources 8 .…”