Intermolecular hydrogen bonding of the two independent molecules of N-3,5-dinitrobenzoyl-L-leucine

The title compound, C₁₃H₁₅N₃O₇, crystallizes as two independent molecules which differ in their conformation. Intermolecular hydrogen bonding between the amide and carboxylic acid groups as N-H...O=C interactions results in the formation of one-dimensional chains with N...O distances of 2.967 (6) and 3.019 (6) Å. Neighbouring chains are linked by C=O...H-O interactions to form a two-dimensional network, with O...O distances of 2.675 (6) and 2.778 (6) Å

Steady-state crystallization of Rydberg excitations in an optically driven lattice gas

We study resonant optical excitations of atoms in a one-dimensional lattice to the Rydberg states interacting via the van der Waals potential which suppresses simultaneous excitation of neighboring atoms. Considering two- and three-level excitation schemes, we analyze the dynamics and stationary state of the continuously-driven, dissipative many-body system employing time-dependent density-matrix renormalization group (t-DMRG) simulations. We show that two-level atoms can exhibit only nearest neighbor correlations, while three-level atoms under dark-state resonant driving can develop finite-range crystalline order of Rydberg excitations. We present an approximate rate equation model whose analytic solution yields qualitative understanding of the numerical results.Comment: 5 pages,3 figure

One-dimensional Rydberg Gas in a Magnetoelectric Trap

We study the quantum properties of Rydberg atoms in a magnetic Ioffe-Pritchard trap which is superimposed by a homogeneous electric field. Trapped Rydberg atoms can be created in long-lived electronic states exhibiting a permanent electric dipole moment of several hundred Debye. The resulting dipole-dipole interaction in conjunction with the radial confinement is demonstrated to give rise to an effectively one-dimensional ultracold Rydberg gas with a macroscopic interparticle distance. We derive analytical expressions for the electric dipole moment and the critical linear density of Rydberg atoms.Comment: 4 pages, 2 figure

Rydberg-Atom Population Transfer By Population Trapping in a Chirped Microwave Pulse

We demonstrate that Rydberg atoms can be transferred to states of lower principal quantum number by exposing them to a frequency chirped microwave pulse. Specifically, we have transferred n=75 atoms to n=66 with a 400-ns pulse chirped from 7.8 to 11.8 GHz. In spite of the large number of coupled levels, using a simplified model we can describe the process reasonably well as a sequence of adiabatic rapid passages

Rydberg-Atom Population Transfer By Population Trapping in a Chirped Microwave Pulse

We demonstrate that Rydberg atoms can be transferred to states of lower principal quantum number by exposing them to a frequency chirped microwave pulse. Specifically, we have transferred n=75 atoms to n=66 with a 400-ns pulse chirped from 7.8 to 11.8 GHz. In spite of the large number of coupled levels, using a simplified model we can describe the process reasonably well as a sequence of adiabatic rapid passages

Quantum information processing with single photons and atomic ensembles in microwave coplanar waveguide resonators

We show that pairs of atoms optically excited to the Rydberg states can strongly interact with each other via effective long-range dipole-dipole or van der Waals interactions mediated by their non-resonant coupling to a common microwave field mode of a superconducting coplanar waveguide cavity. These cavity mediated interactions can be employed to generate single photons and to realize in a scalable configuration a universal phase gate between pairs of single photon pulses propagating or stored in atomic ensembles in the regime of electromagnetically induced transparency

Microwave Ionization of an Atomic Electron Wave Packet

A short microwave pulse is used to ionize a lithium Rydberg wave packet launched from the core at a well-defined phase of the field. We observe a strong dependence on the relative phase between the motion of the wave packet and the oscillations of the field. This phase dependent ionization is also studied as a function of the relative frequency. Our experimental observations are in good qualitative agreement with a one-dimensional classical model of wave packet ionization

Microwave Ionization of an Atomic Electron Wave Packet

A short microwave pulse is used to ionize a lithium Rydberg wave packet launched from the core at a well-defined phase of the field. We observe a strong dependence on the relative phase between the motion of the wave packet and the oscillations of the field. This phase dependent ionization is also studied as a function of the relative frequency. Our experimental observations are in good qualitative agreement with a one-dimensional classical model of wave packet ionization

Intramolecular C-H...O and intermolecular N-H...O and C-H...O interactions in N-ferrocenoylglycine benzyl ester, an effective dihydrogen phosphate anion sensing agent

The title compound, benzyl N-(ferrocenecarbonyl)glycinate, [Fe(C₅H₅)(C₁₅H₁₄NO₃)], a glycine benzyl ester derivative, is an effective anion sensor for electrochemically sensing the dihydrogen phosphate anion (H₂PO₄-). Intermolecular N--H...O hydrogen bonds form onedimensional chains with graph set C(4) [N...O 2.811 (3)Å,]. A two-dimensional network is formed by linking the chains through Car--H...0=Cester interactions about inversion centres [graph set R²₂(14); C...O 3.406 (4)Å]. An intramolecular Ccp-H...0=Cester interaction [C...O 3.540 (3)Å,] with graph set S(9) completes the hydrogen bonding

Population Trapping in Extremely Highly Excited States in Microwave Ionization

When a lithium atom in a Rydberg state (n 80) is exposed to a short, intense microwave pulse we find that substantial population is left in extremely highly excited states (n . 120), in spite of the fact that the microwave field amplitude is more than 40 times larger than required to classically ionize these states