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We discuss the expansion dynamics under mean-field repulsion of an array of 87Rb Bose-Einstein condensates produced in an all-optical scheme involving 1D lattice with nearly 105 atoms, after fast evaporative cooling of just about 1 s. Single site occupation exceeds 2 × 104 in our experiments. The possibility of transition to two-dimensionality was also investigated. The expansion behavior of the high density multiple micro-condensates produced directly in the CO2 laser 1D optical lattice, with a lattice spacing of 5.3 μm, agrees well with a numerical simulation based on the mean-field theory. [ABSTRACT FROM AUTHOR]

We describe the realization of Bose-Einstein condensates (BEC) of 87Rb atoms with relatively large number of atoms at high density, in laser-optical traps in our laboratory. Starting from a giant magneto-optical trap containing nearly 1010 atoms, we transfer about 5 x 107 atoms into the optical dipole trap formed by crossing two high-power focused CO2 laser beams. BEC containing about 105 atoms was produced by forced evaporative cooling of the atomic sample in the crossed optical trap down to about 140 nK, in just about a second. The BEC was also produced in a 1D optical lattice formed by the standing wave of a retroreflected focused CO2 laser beam, with about 80,000 atoms in the condensate. Effects of mean-field interaction characteristic of BEC were observed in the expansion dynamics of the condensate. We discuss both the techniques and the innovations that enabled the efficient execution of the multiple steps involved in producing the BEC, starting from a thermal sample of rubidium gas. [ABSTRACT FROM AUTHOR]

In this Note we describe the design, construction, and calibration of an electronic wavelength-meter using a wavelength-sensitive dual-output photodiode. The device was constructed using electronic circuitry and then calibrated using various laser sources in the wavelength range 500-850 nm. This is an inexpensive device compared to the other similar devices available commercially. It is very useful for the determination of the wavelengths of diode lasers. It works well with multi-mode light, and there are no stringent alignment requirements. It is extremely compact and essentially a "pocket wavemeter." The wavelength range for the operation of the wavelength-meter is 450 to 900 nm and it gives 1-3 nm accuracy, depending on the wavelength. [ABSTRACT FROM AUTHOR]

We present the design, implementation, and detailed experimental characterization and comparison with numerical simulations of two-dimensional magneto-optical traps (MOTs) of bosonic 23Na and 39K atoms for loading the cold atomic mixture in a dual-species 3DMOT with a large number of atoms. We report our various measurements pertaining to the characterization of two 2D+MOTs via the capture rate in the 3DMOT and also present the optimized parameters for the best performance of the system of the cold atomic mixture. Under the optimized condition, we capture more than 3 × 101039K atoms and 5.8 × 10823Na atoms in the 3DMOT simultaneously from individual 2D+MOTs with a capture rate of 5 × 1010 and 3.5 × 108 atoms/sec for 39K and 23Na, respectively. We also demonstrate improvements of more than a factor of 5 in the capture rate in the 3DMOT from the cold atomic sources when a relatively high-power ultraviolet light is used to cause light-induced atomic desorption in the 2D+MOT glass cells. A detailed study of the light assisted interspecies cold collisions between the co-trapped atoms is presented, and interspecies loss coefficients have been determined to be βNaK ∼ 2 × 10−12 cm3/sec. The cold atomic mixture would be useful for further experiments on quantum simulation with ultra-cold quantum mixtures in optical potentials. [ABSTRACT FROM AUTHOR]

We investigate the momentum-dependent transport of 1D quasicondensates in quasiperiodic optical lattices. We observe a sharp crossover from a wealdy dissipative regime to a strongly unstable one at a disorder-dependent critical momentum. In the limit of nondisordered lattices the observations suggest a contribution of quantum phase slips to the dissipation. We identify a set of critical disorder and interaction strengths for which such critical momentum vanishes, separating a fluid regime from an insulating one. We relate our observation to the predicted zero-temperature superfluid-Bose glass transition. [ABSTRACT FROM AUTHOR]

We present the development and characterization of a generic, reconfigurable, low-cost (< 350$) software-defined digital receiver system (DRS) for temporal correlation measurements in atomic spin ensembles. We demonstrate the use of the DRS as a component of a high-resolution magnetometer. Digital receiver-based fast Fourier transform spectrometers (FFTSs) are generally superior in performance in terms of signal-to-noise ratio (SNR) compared with traditional swept-frequency spectrum analyzers (SFSAs). In applications where the signals being analyzed are a very narrow band in the frequency domain, recording them at high speeds over a reduced bandwidth provides flexibility to study them for longer periods. We have built the DRS on the STEMLab 125-14 FPGA platform, and it has two different modes of operation: FFT spectrometer and real-time raw voltage recording mode. We evaluate its performance by using it in atomic spin noise spectroscopy (SNS). We demonstrate that the SNR is improved by more than one order of magnitude with the FFTS compared with that of the commercial SFSA. We also highlight that with this DRS operating in the triggered data acquisition mode, one can achieve a spin noise (SN) signal with high SNR in a recording time window as low as 100 ms. We make use of this feature to perform time-resolved high-resolution magnetometry. While the receiver was initially developed for SNS experiments, it can be easily used for other atomic, molecular, and optical (AMO) physics experiments as well. [ABSTRACT FROM AUTHOR]