Many-body treatment of the collisional frequency shift in fermionic atoms.
نویسندگان
چکیده
Recent experiments have measured collisional frequency shifts in polarized fermionic alkaline-earth atoms using 1S0-3P0 Rabi spectroscopy. Here, we provide a first-principles nonequilibrium theoretical description of the interaction frequency shifts starting from the microscopic many-body Hamiltonian. Our formalism describes the dependence of the frequency shift on excitation inhomogeneity, interactions, temperature, and many-body dynamics, provides a fundamental understanding of the effects of the measurement process, and explains the observed density shift data.
منابع مشابه
Precision measurement of fermionic collisions using an 87Sr optical lattice clock with 1 x 10(-16) inaccuracy.
We describe recent progress on the JILA Sr optical frequency standard, which has a systematic uncertainty at the 10(¿16) fractional frequency level. The dominant contributions to the systematic error are from blackbody radiation shifts and collisional shifts. We discuss the blackbody radiation shift and propose measurements and experimental protocols that should reduce its systematic contributi...
متن کاملSuppression of collisional shifts in a strongly interacting lattice clock.
Optical lattice clocks with extremely stable frequency are possible when many atoms are interrogated simultaneously, but this precision may come at the cost of systematic inaccuracy resulting from atomic interactions. Density-dependent frequency shifts can occur even in a clock that uses fermionic atoms if they are subject to inhomogeneous optical excitation. However, sufficiently strong intera...
متن کاملProbing interactions between ultracold fermions.
At ultracold temperatures, the Pauli exclusion principle suppresses collisions between identical fermions. This has motivated the development of atomic clocks with fermionic isotopes. However, by probing an optical clock transition with thousands of lattice-confined, ultracold fermionic strontium atoms, we observed density-dependent collisional frequency shifts. These collision effects were mea...
متن کاملCancellation of the collisional frequency shift in caesium fountain clocks.
We have observed that the collisional frequency shift in primary caesium fountain clocks varies with the clock state population composition and, in particular, is zero for a given fraction of the |F=4,mF=0) atoms, depending on the initial cloud parameters. We present a theoretical model explaining our observations. The possibility of the collisional shift cancellation implies an improvement in ...
متن کاملOptical Trapping and Fundamental Studies of Atomic Fermi Gases
Optical traps provide tight confinement and very long storage times for atomic gases. Using a single focused beam from a CO2 laser, we confine a mixture of spin-up and spin-down fermionic Li atoms, achieving storage times of ten minutes, and evaporative cooling to quantum degeneracy in seconds. A bias magnetic field tunes the gas to a collisional (Feshbach) resonance, producing extremely strong...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Physical review letters
دوره 103 26 شماره
صفحات -
تاریخ انتشار 2009