Rotons in gaseous Bose-Einstein condensates irradiated by a laser.
نویسندگان
چکیده
A gaseous Bose-Einstein condensate irradiated by a far off-resonance laser has long-range interatomic correlations caused by laser-induced dipole-dipole interactions. These correlations, which are tunable via the laser intensity and frequency, can produce a "roton" minimum in the excitation spectrum--behavior reminiscent of the strongly correlated superfluid liquid He II.
منابع مشابه
Transport of Bose-Einstein condensates with optical tweezers.
We have transported gaseous Bose-Einstein condensates over distances up to 44 cm. This was accomplished by trapping the condensate in the focus of an infrared laser and translating the location of the laser focus with controlled acceleration. Condensates of order 10(6) atoms were moved into an auxiliary chamber and loaded into a magnetic trap formed by a Z-shaped wire. This transport technique ...
متن کاملThermodynamic evidence for nanoscale bose-einstein condensation in (4)He confined in nanoporous media.
We report the measurements of the heat capacity of (4)He confined in nanoporous Gelsil glass that has nanopores of 2.5-nm diameter at pressures up to 5.3 MPa. The heat capacity has a broad peak at a temperature much higher than the superfluid transition temperature obtained using the torsional oscillator technique. The peak provides definite thermodynamic evidence for the formation of localized...
متن کاملObservation of vortex pinning in Bose-Einstein condensates.
We report the observation of vortex pinning in rotating gaseous Bose-Einstein condensates. Vortices are pinned to columnar pinning sites created by a corotating optical lattice superimposed on the rotating Bose-Einstein condensates. We study the effects of two types of optical lattice: triangular and square. In both geometries we see an orientation locking between the vortex and the optical lat...
متن کاملEvidence for a Critical Velocity in a Bose-Einstein Condensed Gas
where ́ is the energy of an excitation with momentum p. Critical velocities for the breaking of Cooper pairs in 3He and the generation of rotons [2] and vortices [3] in 4He have been extensively studied. Bose-Einstein condensed gases (BEC) are novel quantum fluids [4]. Previous work has explored some aspects related to superfluidity such as the macroscopic phase [5] and the phonon nature of low-...
متن کاملTemperature Dependence of Vortex Nucleation in Gaseous Bose-Einstein Condensates
The formation of quantized vortices in trapped, gaseous Bose-Einstein condensates is considered. The thermodynamic stability of vortex states and the essential role of the surface excitations as a route for vortex penetration into the condensate are discussed. Special focus is on finite-temperature effects of the vortex nucleation process. It is concluded that the critical angular frequencies f...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 90 11 شماره
صفحات -
تاریخ انتشار 2003