The formation of ultralong-range Rydberg molecules is a result of the attractive interaction between a Rydberg electron and a polarizable ground-state atom in an ultracold gas. In the nondegenerate case, the backaction of the polarizable atom on the electronic orbital is minimal. Here we demonstrate how controlled degeneracy of the respective electronic orbitals maximizes this backaction and le...

We present an efficient method for producing N particle entangled states using Rydberg blockade interactions. Optical excitation of Rydberg states that interact weakly, yet have a strong coupling to a second control state is used to achieve state dependent qubit rotations in small ensembles. On the basis of quantitative calculations, we predict that an entangled quantum superposition state of e...

We show that optical spectroscopy of Rydberg states can provide accurate in situ thermometry at room temperature. Transitions from a metastable state to Rydberg states with principal quantum numbers of 25-30 have 200 times larger fractional frequency sensitivities to blackbody radiation than the strontium clock transition. We demonstrate that magic-wavelength lattices exist for both strontium a...

We report the direct measurement of the van der Waals interaction between two isolated, single Rydberg atoms separated by a controlled distance of a few micrometers. Working in a regime where the single-atom Rabi frequency for excitation to the Rydberg state is comparable to the interaction, we observe partial Rydberg blockade, whereby the time-dependent populations of the various two-atom stat...

We present photoionization spectra of C2H5I and C6H6 doped into Ar and SF6, and photoabsorption spectra of C2H5I doped into Ar. The observation of subthreshold photoionization in C2H5I/SF6 and C6H6/SF6 is discussed in terms of dopant (D)/perturber (P) interactions involving the excited state processes of D + P 6 D + P and D + P 6 [DP] + e, where D is a discrete Rydberg state of the dopant. The ...

We propose and analyze an approach for preparation of high fidelity entanglement and antiferromagnetic states using Rydberg mediated interactions with dissipation. Using asymmetric Rydberg interactions the two-atom Bell singlet is a dark state of the Rydberg pumping process. Master equation simulations demonstrate Bell singlet preparation fidelity F=0.998. Antiferromagnetic states are generated...

We propose and analyze the implementation of a two-qubit quantum gate using circular Rydberg states with maximum orbital angular momentum. The intrinsic quantum gate error is limited by the finite Rydberg lifetime and finite Rydberg blockade shift. Circular states have much longer radiative lifetimes than low orbital angular momentum states and are therefore candidates for high-fidelity gate op...

We theoretically investigate the quantum properties of nS, nP, and nD Rydberg atoms in a magnetic Ioffe-Pritchard trap. In particular, it is demonstrated that the two-body character of Rydberg atoms significantly alters the trapping properties opposed to pointlike particles with identical magnetic moment. Approximate analytical expressions describing the resulting Rydberg trapping potentials ar...

Blockade interactions whereby a single particle prevents the flow or excitation of other particles provide a mechanism for control of quantum states, including entanglement of two or more particles. Blockade has been observed for electrons1–3, photons4 and cold atoms5. Furthermore, dipolar interactions between highly excited atoms have been proposed as a mechanism for ‘Rydberg blockade’6,7, whi...