mp3ġ48 - 10A - Fredo Bang & YNW Melly - Brazy.mp3ġ50 - 1A - Major Lazer - Roll The Bass. mp3ġ46 - 6A - Gent & Jawns - Moon Bounce. mp3ġ40 - 12A - Coi Leray & Nicki Minaj - Blick Blick. ![]() mp3ġ08 - 6A - Starjack & Collini x Maitre Gims - Loin. mp3ġ05 - 11A - TWRK & Lambo - Independent. mp3ġ00 - 8B - Willy William, Will.I.Am & Lali - Solo. mp3ġ00 - 8A - DJ Jeff x Daddy Yankee & Myke Towers - Pasatiempo. mp3ġ00 - 4A - Missy Elliott - Get Ur Freak On. mp3ġ00 - 2A - DJ Neo x DJ Jonel Sagayno Remix - Mahal Ang Gasolina Umabot Na Otyenta. mp3ġ00 - 2A - Big Sean, DJ Chose - IDFWU. An absorption image is taken after a variable-length time of flight (TOF).100 - 10A - DJ Moutie x Pop Smoke Vs. ![]() The molasses phase is only used in Sec. 5. After a 10 s accumulation, the 767 nm trap is extinguished, the 767 nm repump intensity is reduced, and the 405 nm trap is turned on for a variable hold time. Inset: Timing diagram of laser beam intensities (top three lines) and magnetic field strength. The potassium (K) cloud is imaged in absorption with a probe beam (not shown). The magnetic quadrupole (QP) coils typically apply 10 G/cm along their strong axis. Only one MOT direction has been shown for clarity, but there is an identical beam path in three orthogonal directions. Each DWP has a quarter-wave retardation at one wavelength and no retardation at the other wavelength. The two colors are mixed on a dichroic mirror (DM), manipulated with dichroic quarter-wave plates (DWPs), and retroreflected off a broadband mirror (BBM). Reuse & Permissionsįigure 3The optical configuration of the magneto-optical trap includes 767 nm trapping and repump beams (both shown with red dashed outlines) and a 405 nm trapping beam (shown in solid blue). The solid blue and dashed red arrows indicate the cooling and repump hyperfine transitions, respectively, used for laser cooling. Hyperfine splittings Δ E referenced to the level energies are from for 4 S 1 / 2 and 5 P 3 / 2, from for 4 P 3 / 2, and given in frequency units (as Δ E / h). Level energies E referenced from the 4 S state are from and presented in both frequency units (as E / h) and wavelength units (in italics, as h c / E). The total measured lifetime from all decay channels is 134(2) ns for 5 P 3 / 2 and 137.6(1.3) ns for 5 P 1 / 2. The uncertainties in the 5 P → 4 S rates are less than 8 %, but all other rates are estimated to have uncertainties between 25% and 50%. Except for 4 P → 4 S (from ), the uncertainties in transition probability rates are not shown explicitly. Transition probabilities are from and listed as A = 1 / τ in units of μ s − 1. A qualitatively similar enhancement is observed in a 405 nm MOT of bosonic 41K.įigure 1Level diagram including all the possible decay channels of the 4 S → 5 P transition in 40K. The combined temperature and density improvement in the 405 nm MOT is a twenty-fold increase in phase-space density over our 767 nm MOT, showing enhanced precooling for quantum gas experiments. We measure a two-body loss coefficient of β = 1.4 ( 1 ) × 10 − 10 cm 3/s near saturation intensity, and estimate an upper bound of 8 × 10 − 18 cm 2 for the ionization cross section of the 5 P state at 405 nm. The density of trapped atoms also increases, due to reduced temperature and reduced expulsive light forces. Because the 5 P 3 / 2 state has a smaller linewidth than the 4 P 3 / 2 state, the Doppler limit is reduced from 145 μK to 24 μK, and we observe temperatures as low as 63(6) μK. Fermionic 40K is captured using a magneto-optical trap (MOT) on the closed 4 S 1 / 2 → 4 P 3 / 2 transition at 767 nm and then transferred, with high efficiency, to a MOT on the open 4 S 1 / 2 → 5 P 3 / 2 transition at 405 nm. ![]() ![]() We report the laser cooling and trapping of neutral potassium on an open transition.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |