Ultralong-Range Interactions and Blockade of Excitation in a Cold Rydberg Gas

Abstract

Articles you may be interested inMagnetic-film atom chip with 10 μm period lattices of microtraps for quantum information science with Rydberg atoms Rev. Sci. Instrum. 85, 053102 (2014); Abstract. We review our recent experiments on interaction-induced effects in a gas of Rydberg atoms excited from a laser-cooled rubidium cloud. The van-der-Waals interaction between a pair of Rydberg atoms separated as far as 100,000 Bohr radii features two important effects: Spectral broadening of the resonance lines and suppression of excitation with increasing Rydberg density. The line broadenings are interpreted in terms of level shifts of Rydberg pairs due to their interaction. The density-dependent suppression of excitation marks the onset of an interaction-induced local blockade.

Ultracold Molecules Formed by Photoassociation: Heteronuclear Dimers, Inelastic Collisions, and Interactions with Ultrashort Laser Pulses

“…They present an extensive discussion of ultracold Cs 2 molecule formation that exemplifies typical experimental techniques. The monograph edited by Weidemüller and Zimmermann gives a general, textbook-style overview over the physics of ultracold atoms and molecules. The reviews by Doyle et al, Hutson and Soldán, Friedrich and Doyle, Carr et al, Bell and P. Softley, and Dulieu and Gabbanini comprehensively cover the state of the art of the physics and chemistry with ultracold molecules.…”

Quantum sensing protocol for motionally chiral Rydberg atoms

“…We suggest to use dressed Rydberg atoms as sensitive quantum sensors [4] for chirality exploiting the long lifetimes of sensitive Rydberg states and accurate clock states featured in the hyperfine manifold of the electronic ground state of alkali metals, which are the basis of the current definition of time. Using twophoton dressing from one of the hyperfine levels of the electronic ground states to a Rydberg state we can combine an accurate reference with a sensitive Rydberg state such that interaction-induced energy shifts [5][6][7] are not probed directly by spectroscopy on the Rydberg state [8][9][10] but are translated to energy shifts of the clock states. Employing a Ramsey sensing sequence [11] these energy shifts can be accurately determined (Fig.…”

“…We insert the atom-field coupling into the above formula and retain only the leading-order chiral contributions which are due to cross-terms of electric-dipole and Röntgen couplings. Evaluating the matrix elements by means of the field expansions ( 2) and (3) and using the completeness relation (5), we find (7) with atomic transition frequencies ω nk = (E n − E k )/ , the electric dipole matrix elements d nk = n| d|k and the Cauchy principal value P. As a consistency check, we note that the above energy shift hence vanishes when (i) the dipole moments are linearly polarised (d nk = d kn ) and hence the atom does not exhibit handedness. Upon splitting the Green tensor G = G (0) + G (1) into its bulk and scattering parts G (0) and G (1) , respectively, the former does not contribute due to the symmetry G (0) (r, r ) = G (0) (r , r).…”