Related papers: Dual-wavelength active optical clock
The influence of external pressure on the charge-density-wave (CDW) ground state of the quasi-one-dimensional two-leg ladder compound Sr$_{10}$Ca$_{4}$Cu$_{24}$O$_{41}$ has been studied by optical reflectivity measurements as a function of…
Atoms coupled to cavities provide an exciting playground for the study of fundamental interactions of atoms mediated through a common channel. Many of the applications of cavity-QED and cold-atom experiments more broadly, suffer from…
Circularly polarized photoluminescence (PL) spectroscopy measured at 19 K on GaAs/AlGaAs symmetric and asymmetric double quantum wells (DQW) is reported. The PL is obtained by exciting the sample with a circularly polarized (left or right)…
An ideal superradiant laser on an optical clock transition of noninteracting cold atoms is predicted to exhibit an extreme frequency stability and accuracy far below mHz-linewidth. In any concrete setup sufficiently many atoms have to be…
Possibilities to search for double beta decay of alpha/beta unstable nuclei, many of which have higher energy release than "conventional" (beta stable) double beta decay candidates, are discussed. First experimental half-life limits on…
We have examined a subset of 11 active galactic nuclei (AGN) drawn from a sample of 87 objects that possess double-peaked optical emission line spectra, as put forward by Wang et al. (2009a) and are detectable in the FIRST survey at radio…
Metal halide perovskites have emerged as promising gain materials for on-chip lasers in photonic integrated circuits (PICs). However, stable continuous wave (CW) lasing behavior under optical pumping at room temperature - a prerequisite for…
We report on Doppler-free laser spectroscopy in a Cs vapor cell using a dual-frequency laser system tuned on the Cs D$_1$ line. Using counter-propagating beams with crossed linear polarizations, an original sign-reversal of the usual…
As superconductors are thinned down to the 2D limit, their critical temperature $T_c$ typically decreases. Here we report the opposite behavior, a substantial enhancement of $T_c$ with decreasing thickness, in 2D crystalline superconductor…
It is widely believed that the generation of high speed optical signals is not the job for an LED. However this work is done to show that there are techniques which can be used to produce nanosecond square pulses from a diode. Rise and fall…
We report the observation of two-fold rotation symmetry in charge density wave (CDW) state in the newly discovered Kagome superconductor CsV$_3$Sb$_5$. Below its CDW transition temperature ($T_{CDW}$), the polarization rotation of the…
The realization of ultra-stable lasers with $10^{-17}$-level frequency stability has enabled a wide range of researches on precision metrology and fundamental science, where cryogenic single-crystalline cavities constitute the heart of such…
Beat note measurements between a mode-locked and a continuous-wave laser as well as between two mode-locked sources were used to demonstrate that the sub-threshold, cavity filtered, amplified spontaneous emission is not stationary even when…
Intracavity frequency-doubled solid-state lasers exhibit intensity fluctuations of their light output, which are cause by nonlinear dynamical processes. Up to now, there are different solutions to this problem, but they reduce the output…
We study self sustained cavity emission from driven atoms in collective strong coupling. The cavity emission occurs over a wide range of atom-cavity and drive laser detunings without any external input to the cavity mode. Second order…
Dual-comb spectroscopy has emerged as an indispensable analytical technique in applications that require high resolution and broadband coverage within short acquisition times. Its experimental realization, however, remains hampered by…
A microwave atomic clock scheme based on Rb and Cs atoms trapped in optical lattice with magic wavelength for clock transition is proposed. The ac Stark shift of clock transition due to trapping laser can be canceled at some specific laser…
Integrated photonics in trapped-ion systems are critical for the realization of applications such as portable optical atomic clocks and scalable quantum computers. However, system-level integration of all required functionalities remains a…
Cuprate materials hosting high-temperature superconductivity (HTS) also exhibit various forms of charge and/or spin ordering whose significance is not fully understood. To date, static charge-density waves (CDWs) have been detected by…
We investigate single cesium (Cs) atom heating owing to the momentum accumulation process induced by the resonant pulsed excitation in a microscopic optical dipole trap formed by a strongly focused 1064 nm laser beam. The heating depends on…