We simulate the effect of special excitation pulses on a cold gas of atoms. First, a rotary echo sequence is used to examine the coherent nature of a frozen Rydberg gas. If collective excitation and de-excitation is present with little or no source of dephasing, after these pulses the system should be returned to a state with few excitations, and a strong echo signal should occur. We investigate systems that should display a perfect echo and systems where the interaction between atoms reduces the echo signal. A spin echo sequence is also used on a system of coherent hopping excitations, and we simulate how the strength of a spin echo signal is affected by thermal motion.We simulate the effect of special excitation pulses on a cold gas of atoms. First, a rotary echo sequence is used to examine the coherent nature of a frozen Rydberg gas. If collective excitation and de-excitation is present with little or no source of dephasing, after these pulses the system should be returned to a state with few excitations, and a strong echo signal should occur. We investigate systems that should display a perfect echo and systems where the interaction between atoms reduces the echo signal. A spin echo sequence is also used on a system of coherent hopping excitations, and we simulate how the strength of a spin echo signal is affected by thermal motion.

Journal of Physics B Atomic Molecular and Optical PhysicsSep 10, 200817 citations

Coherence and Decoherence in Rydberg Gases

P. Pillet, D. Comparat, M. Muldrich +8 more

Springer eBooksDec 13, 20052 citations

Coherent manipulation of cold Rydberg atoms near the surface of an atom chip

J. D. Carter, J. D. D. Martin

Coherent superpositions of the $49{s}_{1/2}$ and $48{s}_{1/2}$ Rydberg states of cold ${}^{87}$ Rb atoms were studied near the surface of an atom chip. The superpositions were created and manipulated using microwaves resonant with the two-photon $49{s}_{1/2}\ensuremath{-}48{s}_{1/2}$ transition. Coherent behavior was observed using Rabi flopping, Ramsey sequences, spin echo, and spin locking. These results are discussed in the context of Rydberg atoms as electric field noise sensors. We consider the coherence of systems quadratically coupled to noise fields with $1/{f}^{\ensuremath{\kappa}}$ power spectral densities ($\ensuremath{\kappa}\ensuremath{\approx}1$).Coherent superpositions of the $49{s}_{1/2}$ and $48{s}_{1/2}$ Rydberg states of cold ${}^{87}$Rb atoms were studied near the surface of an atom chip. The superpositions were created and manipulated using microwaves resonant with the two-photon $49{s}_{1/2}\ensuremath{-}48{s}_{1/2}$ transition. Coherent behavior was observed using Rabi flopping, Ramsey sequences, spin echo, and spin locking. These results are discussed in the context of Rydberg atoms as electric field noise sensors. We consider the coherence of systems quadratically coupled to noise fields with $1/{f}^{\ensuremath{\kappa}}$ power spectral densities ($\ensuremath{\kappa}\ensuremath{\approx}1$).

arXiv:1308.1945Physical Review AOct 28, 201341 citations

In situRamsey interferometry and diffraction echo with an atomic Fermi gas

C. Marzok, Benjamin Deh, Sebastian Slama +2 more

We report on the observation of Bragg diffraction of a spin-polarized ultracold $^{6}\mathrm{Li}$ Fermi gas and demonstrate a Ramsey-type matter-wave interferometer. Suppression of $s$ -wave collisions by the Pauli principle allows for unperturbed dynamics of the atoms in the trap for longer than $2\phantom{\rule{0.3em}{0ex}}\mathrm{s}$ . Employing an echo pulse sequence, we observe coherent superpositions of momentum states which do not show any sign of decoherence during the experimentally limited observation time of $100\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{s}$. In contrast, significant decoherence is observed in the presence of a cold cloud of $^{87}\mathrm{Rb}$ atoms. The experiment demonstrates the feasibility of high-resolution atomic interferometry with applications for precision measurements in small volumes and near surfaces.We report on the observation of Bragg diffraction of a spin-polarized ultracold $^{6}\mathrm{Li}$ Fermi gas and demonstrate a Ramsey-type matter-wave interferometer. Suppression of $s$-wave collisions by the Pauli principle allows for unperturbed dynamics of the atoms in the trap for longer than $2\phantom{\rule{0.3em}{0ex}}\mathrm{s}$. Employing an echo pulse sequence, we observe coherent superpositions of momentum states which do not show any sign of decoherence during the experimentally limited observation time of $100\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{s}$. In contrast, significant decoherence is observed in the presence of a cold cloud of $^{87}\mathrm{Rb}$ atoms. The experiment demonstrates the feasibility of high-resolution atomic interferometry with applications for precision measurements in small volumes and near surfaces.

arXiv:0804.0532Physical Review AAug 12, 20085 citations

Coherent superpositions of the

49{s}_{1/2}

and

48{s}_{1/2}

Rydberg states of cold

{}^{87}

Rb atoms were studied near the surface of an atom chip. The superpositions were created and manipulated using microwaves resonant with the two-photon $49{s}_{1/2}\ensuremath{-}48{s}_{1/2}$ transition. Coherent behavior was observed using Rabi flopping, Ramsey sequences, spin echo, and spin locking. These results are discussed in the context of Rydberg atoms as electric field noise sensors. We consider the coherence of systems quadratically coupled to noise fields with $1/{f}^{\ensuremath{\kappa}}$ power spectral densities ($\ensuremath{\kappa}\ensuremath{\approx}1$).

We report on the observation of Bragg diffraction of a spin-polarized ultracold

^{6}\mathrm{Li}

Fermi gas and demonstrate a Ramsey-type matter-wave interferometer. Suppression of

s

-wave collisions by the Pauli principle allows for unperturbed dynamics of the atoms in the trap for longer than

2\phantom{\rule{0.3em}{0ex}}\mathrm{s}

. Employing an echo pulse sequence, we observe coherent superpositions of momentum states which do not show any sign of decoherence during the experimentally limited observation time of $100\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{s}$. In contrast, significant decoherence is observed in the presence of a cold cloud of

^{87}\mathrm{Rb}

atoms. The experiment demonstrates the feasibility of high-resolution atomic interferometry with applications for precision measurements in small volumes and near surfaces.