Related papers: S-Wave Collisional Frequency Shift of a Fermion Cl…
We excite spin-waves with spatially inhomogeneous pulses and study the resulting frequency shifts of a chip-scale atomic clock of trapped $^{87}$Rb. The density-dependent frequency shifts of the hyperfine transition simulate the s-wave…
Collisions with background gas can perturb the transition frequency of trapped ions in an optical atomic clock. We develop a non-perturbative framework based on a quantum channel description of the scattering process, and use it to derive a…
We theoretically study the effects of elastic collisions on the determination of frequency standards via Ramsey fringe spectroscopy in optical-lattice atom clocks. Interparticle interactions of bosonic atoms in multiply-occupied lattice…
At ultracold temperatures, the Pauli exclusion principle suppresses collisions between identical fermions. This has motivated the development of atomic clocks using fermionic isotopes. However, by probing an optical clock transition with…
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…
We analyze both the s- and p-wave collision induced frequency shifts and propose a over-$\pi$ pulse scheme to cancel the shifts in optical lattice clocks interrogated by a Rabi pulse. The collisional frequency shifts are analytically solved…
Optical lattice clocks have the potential for extremely high frequency stability owing to the simultaneous interrogation of many atoms, but this precision may come at the cost of systematic inaccuracy due to atomic interactions.…
We develop a formalism to incorporate exchange symmetry considerations into the calculation of collisional frequency shifts and blackbody radiation effects for atomic clock transitions using a density matrix formalism. The formalism is…
We present non-standard optical Ramsey schemes that use pulses individually tailored in duration, phase, and frequency to cancel spurious frequency shifts related to the excitation itself. In particular, the field shifts and their…
Collisions between background gas particles and the trapped ion in an atomic clock can subtly shift the frequency of the clock transition. The uncertainty in the correction for this effect makes a significant contribution to the total…
We perform exact calculations of collisional frequency shifts for several fermions or bosons using a singlet and triplet basis for pairs of particles. The "factor of 2 controversy" for bosons becomes clear - the factor is always 2.…
We consider the frequency shift in optical lattice clocks which arises from the coupling of the electronic motion to the atomic motion within the lattice. For the simplest of 3-D lattice geometries this coupling is shown to only affect…
We demonstrate a one-dimensional optical lattice clock with a spin-polarized fermionic isotope designed to realize a collision-shift-free atomic clock with neutral atom ensembles. To reduce systematic uncertainties, we developed both Zeeman…
Collisions with background gas particles can shift the resonance frequencies of atoms in atomic clocks. The internal quantum states of atoms can also become entangled with their motional states due to the recoil imparted by a collision,…
Motivated by the ideas of using cold alkaline earth atoms trapped in an optical lattice for realization of optical atomic clocks, we investigate theoretically the perturbative effects of atom-atom interactions on a clock transition…
Frequency shifts from background gas collisions currently contribute significantly to the inaccuracy of atomic clocks. Because nearly all collisions with room-temperature background gases that transfer momentum eject the cold atoms from the…
We develop the method of Ramsey spectroscopy with the use of an additional field compensating the frequency shifts of clock optical transitions. This method in combination with the method of magnetically induced excitation of strongly…
We study ultracold collisions in fermionic ytterbium by precisely measuring the energy shifts they impart on the atom's internal clock states. Exploiting Fermi statistics, we uncover p-wave collisions, in both weakly and strongly…
We derive universal relations for the radio-frequency (rf) spectroscopy of a two-dimensional Fermi gas consisting of two spin states with a resonant S-wave interaction. The rf transition rate has a high-frequency tail that is proportional…
We have extended Ramsey spectroscopy by stepping the probe frequency during the two Ramsey excitation pulses to compensate frequency shifts induced by the excitation itself. This makes precision Ramsey spectroscopy applicable even for…