Zobrazeno 1 - 10
of 75
pro vyhledávání: '"GEHM, M. E."'
We construct a terahertz time-domain spectrometer (THz-TDS) system based on photoconductive antenna (PCA). A 800 nm Ti sapphire femtosecond laser with 80 MHz repetition rate provides the pump and probe laser pulse, which has a 45 fs pulse width (as s
Externí odkaz:
http://arxiv.org/abs/1402.1997
Publikováno v:
Phys. Rev. Lett. 92, 150402 (2004)
We observe collective oscillations of a trapped, degenerate Fermi gas of $^6$Li atoms at a magnetic field just above a Feshbach resonance, where the two-body physics does not support a bound state. The gas exhibits a radial breathing mode at a freque
Externí odkaz:
http://arxiv.org/abs/cond-mat/0403540
We derive the elastic collision rate for a harmonically-trapped Fermi gas in the extreme unitarity limit where the s-wave scattering cross section is $\sigma (k) =4\pi/k^2$, with $\hbar k$ the relative momentum. The collision rate is given in the for
Externí odkaz:
http://arxiv.org/abs/cond-mat/0304633
A strongly-attractive, two-component Fermi gas of atoms exhibits universal behavior and should be mechanically stable as a consequence of the quantum mechanical requirement of unitarity. This requirement limits the maximum attractive force to a value
Externí odkaz:
http://arxiv.org/abs/cond-mat/0212499
Publikováno v:
Science Dec 13 2002: 2179-2182
We report on the observation of a highly-degenerate, strongly-interacting Fermi gas of atoms. Fermionic $^6$Li atoms in an optical trap are evaporatively cooled to degeneracy using a magnetic field to induce strong, resonant interactions. Upon abrupt
Externí odkaz:
http://arxiv.org/abs/cond-mat/0212463
Autor:
O'Hara, K. M., Hemmer, S. L., Granade, S. R., Gehm, M. E., Thomas, J. E., Venturi, V., Tiesinga, E., Williams, C. J.
We measure a zero crossing in the scattering length of a mixture of the two lowest hyperfine states of 6-Li. To locate the zero crossing, we monitor the decrease in temperature and atom number arising from evaporation in a CO2 laser trap as a functio
Externí odkaz:
http://arxiv.org/abs/cond-mat/0207717
We achieve degeneracy in a mixture of the two lowest hyperfine states of $^6$Li by direct evaporation in a CO$_2$ laser trap, yielding the first all-optically produced degenerate Fermi gas. More than $10^5$ atoms are confined at temperatures below $4
Externí odkaz:
http://arxiv.org/abs/cond-mat/0111344
Publikováno v:
Phys. Rev. Lett. 85, 2092 (2000)
We use an all-optical trap to confine a strongly attractive two-state mixture of lithium fermions. By measuring the rate of evaporation from the trap, we determine the effective elastic scattering cross section (4 PI a^2) to show that the magnitude o
Externí odkaz:
http://arxiv.org/abs/physics/0009026
Autor:
O'Hara, K. M., Granade, S. R., Gehm, M. E., Savard, T. A., Bali, S., Freed, C., Thomas, J. E.
Publikováno v:
Phys. Rev. Lett. 82, 4204 (1999)
We demonstrate an ultrastable CO2 laser trap that provides tight confinement of neutral atoms with negligible optical scattering and minimal laser-noise- induced heating. Using this method, fermionic 6Li atoms are stored in a 0.4 mK deep well with a
Externí odkaz:
http://arxiv.org/abs/physics/0003049
Autor:
Brady, D. J.1, Gehm, M. E.2, Stack, R. A.3, Marks, D. L.1, Kittle, D. S.1, Golish, D. R.2, Vera, E. M.2, Feller, S. D.1
Publikováno v:
Nature. 6/21/2012, Vol. 486 Issue 7403, p386-389. 4p.
