We study the dynamics of a simple model for quantum decay, where a single state is coupled to a set of discrete states, the pseudocontinuum, each coupled to a real continuum of states. We find that for constant matrix elements between the single state and the pseudocontinuum the decay occurs via one...

We propose a geometric phase gate of two ion qubits that are encoded in two levels linked by an optical dipole-forbidden transition. Compared to hyperfine geometric phase gates mediated by electric dipole transitions, the gate has many interesting properties, such as very low spontaneous emission ra...

The best qubit one-way quantum-key-distribution (QKD) protocol can tolerate up to 14.6% in the error rate. It has been shown how this rate can be increased by using larger quantum systems. The polarization state of a biphoton can encode a three-level quantum system—a qutrit. The realization of a Q...

Entangling two systems at distant locations using a separable mediating ancilla is a counterintuitive phenomenon proposed for qubits by T. Cubitt [Phys. Rev. Lett. 91, 037902 (2003)]. We show that such entanglement distribution is possible with Gaussian states, using a certain three-mode fully sepa...

We show how to efficiently generate pseudorandom states suitable for quantum information processing via cluster-state quantum computation. By reformulating pseudorandom algorithms in the cluster-state picture, we identify a strategy for optimizing pseudorandom circuits by properly choosing single-qu...

We experimentally investigate nonlinear couplings between individual quanta of the vibrational modes of strings of cold ions stored in linear ion traps. The nonlinearity is caused by the ions’ Coulomb interaction and gives rise to a Kerr-type interaction Hamiltonian H=ℏχn̂_rn̂_s , where n̂_r ...

An experimental scheme is proposed that allows direct measurement of the concurrence of a two-qubit cavity system. It is based on the cavity-QED technology using atoms as flying qubits and relies on the identity of the two-particle visibility of the atomic probability with the concurrence of the cav...

We consider the dynamics of a vibrating and rotating end mirror of an optical Fabry-Pérot cavity that can sustain Laguerre-Gaussian modes. We demonstrate theoretically that since the intracavity field carries linear as well as angular momentum, radiation pressure can create bipartite entanglement b...

We report an uncertainty evaluation of an optical lattice clock based on the ¹S₀↔³P₀ transition in the bosonic isotope ¹⁷⁴Yb by use of magnetically induced spectroscopy. The absolute frequency of the ¹S₀↔³P₀ transition has been determined through comparisons with optical and microwave stan...

Absolute cross sections for the production of the two astronomy-relevant negative ions HCC⁻ and HCCCC⁻ by dissociative electron attachment to acetylene C₂H₂ and diacetylene C₄H₂ were measured (with a ±25% error bar). Acetylene yielded the C₂H⁻ ion at an electron ...

Above 54.4   eV , two-photon double ionization of helium is dominated by a sequential absorption process, producing characteristic behavior in the single and triple differential cross sections. We show that the signature of this process is visible in the nuclear recoil cross section, integrate...

We present a rigorous study of vibrational relaxation in para-H₂+para-H₂ collisions at cold and ultracold temperatures and identify an efficient mechanism of rovibrational energy transfer. If the colliding molecules are in different rotational and vibrational levels, the internal energy may be tra...

Energy absorption of xenon clusters embedded in helium nanodroplets from strong femtosecond laser pulses is studied theoretically. Compared to pure clusters we find earlier and more efficient energy absorption in agreement with experiments. This effect is due to resonant absorption of the helium nan...

We show that a laser pulse designed as an adiabatic ramp followed by a kick allows one to reach a perfect postpulse molecular alignment, free of saturation. The mechanism is based on an optimized distribution of the energy between a weakly efficient but nonsaturating adiabatic ramp and an efficient ...

We demonstrate that the structure of CO₂ molecules can be determined by measuring the phases of harmonics from them. This is evidenced by observing a phase jump of harmonics generated in a mixed gas of aligned CO₂ molecules and their reference Kr atoms, which serve to extract the net contributio...

The ionization of H₂ in intense laser pulses is studied by numerical integration of the time-dependent Schrödinger equation for a single-active-electron model including the vibrational motion. The electron kinetic-energy spectra in high-order above-threshold ionization are strongly dependent on t...

Alignment dependence of structural deformation in the production process of multiply charged CO₂ molecules in an intense femtosecond laser field has been revealed by using aligned sample molecules. Our properly ordered observations clarify that the structural change takes place in the charge state...

Quantum systems with Hofstadter’s butterfly spectrum are of fundamental interest to many research areas. Based upon slight modifications of existing cold-atom experiments, a cold-atom realization of quantum maps with Hofstadter’s butterfly spectrum is proposed. Connections and differences betwee...

The study of ultracold optically trapped atoms has opened new vistas in the physics of correlated quantum systems. Much attention has now turned to mixtures of bosonic and fermionic atoms. A central puzzle is the disagreement between the experimental observation of a reduced bosonic visibility V_b ,...

The local-density approximation is used to study the ground state superfluid properties of harmonically trapped p -wave Fermi gases as a function of fermion-fermion attraction strength. While the density distribution is bimodal on the weakly attracting BCS side, it becomes unimodal with increasing ...

Going beyond the currently investigated regimes in experiments on quantum transport of ultracold atoms in disordered potentials, we predict a crossover between regular and quantum-chaotic dynamics when varying the strength of disorder. Our spectral approach is based on the Bose-Hubbard model describ...

We report on the measurement of the equation of state of a two-component Fermi gas of ⁶Li atoms with resonant interactions. By analyzing the in situ density distributions of a population-imbalanced Fermi mixture reported in a recent experiment [Y. Shin , Nature 451, 689 (2008)], we determine the e...

We consider a longitudinal expansion of a one-dimensional gas of hard-core bosons suddenly released from a trap. We show that the broken translational invariance in the initial state of the system is encoded in correlations between the bosonic occupation numbers in the momentum space. The correlatio...

We present a theory of measurement-induced interference for weakly interacting Bose-Einstein-condensed gases. The many-body state resulting from the evolution of an initial fragmented (Fock) state can be approximated as a continuous superposition of Gross-Pitaevskii (GP) states; the measurement brea...

We present a theoretical study of the collective excitations of a trapped imbalanced fermion gas at unitarity, when the system consists of a superfluid core and a normal outer shell. We formulate the relevant boundary conditions and treat the normal shell both hydrodynamically and collisionlessly. F...

We present experimental results on the coherent transfer of orbital angular momentum (OAM) from optical fields to the center-of-mass motion of a Bose-Einstein condensate (BEC), using an approach which results in negligible linear momentum change. Two collinear optical beams of differing OAM are used...

We investigate the stability and the free expansion of a trapped dipolar Fermi gas. We show that stabilizing the system relying on tuning the trap geometry is generally inefficient. We further show that the expanded density profile always gets stretched along the attractive direction of dipolar inte...

What will happen if two identical microspheres, with fundamental whispering-gallery modes excited in each of them, become optically coupled? Conventional wisdom based on coupled-mode arguments says that two new modes, bonding and antibonding, with two split frequencies would be formed. In this Rapid...

We theoretically investigate image storage in hot atomic vapor. A so-called 4f system is adopted for imaging and an atomic vapor cell is placed over the transform plane. The Fraunhofer diffraction pattern of an object in the object plane can thus be transformed into atomic Raman coherence accordin...

A CCD array is placed facing a chaotic light source and gated by a photon counting detector that simply counts all randomly scattered and reflected photons from an object. A “ghost” image of the object is then observed in the gated CCD. Differing from all published ghost-imaging experiments, thi...

We propose a geometric phase gate of two ion qubits that are encoded in two levels linked by an optical dipole-forbidden transition. Compared to hyperfine geometric phase gates mediated by electric dipole transitions, the gate has many interesting properties, such as very low spontaneous emission ra...

We analyze classically defined games for which a quantum team has an advantage over any classical team. The quantum team has a clear advantage in games in which the players of each team are separated in space and the quantum team can use unusually strong correlations of the Einstein-Podolsky-Rosen t...

The concept of time delayed creation of entanglement by the dissipative process of spontaneous emission is investigated. A threshold effect for the creation of entanglement is found where the initially unentangled qubits can be entangled after a finite time despite the fact that the coherence betwee...

The best qubit one-way quantum-key-distribution (QKD) protocol can tolerate up to 14.6% in the error rate. It has been shown how this rate can be increased by using larger quantum systems. The polarization state of a biphoton can encode a three-level quantum system—a qutrit. The realization of a Q...

Entangling two systems at distant locations using a separable mediating ancilla is a counterintuitive phenomenon proposed for qubits by T. Cubitt [Phys. Rev. Lett. 91, 037902 (2003)]. We show that such entanglement distribution is possible with Gaussian states, using a certain three-mode fully sepa...

Matrix product states can be defined as the family of quantum states that can be sequentially generated in a one-dimensional system [Schön , Phys. Rev. Lett. 95, 110503 (2005)]. We introduce a family of states that extends this definition to two dimensions. Like in matrix product states, expectatio...

Dissipation may cause two initially entangled qubits to evolve into a separable state in a finite time. This behavior is called entanglement sudden death (ESD). We study to what extent quantum error correction can combat ESD. We find that in some cases quantum error correction can delay entanglement...

A linear optical probabilistic scheme for the optimal cloning of a pair of orthogonally polarized photons is devised, based on single- and two-photon interferences. It consists in a partial symmetrization device realized with a modified unbalanced Mach-Zehnder interferometer, followed by two balance...

We make a detailed analysis of error mechanisms, gate fidelity, and scalability of proposals for quantum computation with neutral atoms in addressable (large lattice constant) optical lattices. We have identified possible limits to the size of quantum computations, arising in three-dimensional (3D) ...

Local or nonlocal character of quantum states can be quantified and is subject to various bounds that can be formulated as complementarity relations. Here, we investigate the local vs nonlocal character of pure three-qubit states by a four-way interferometer. The complete entanglement in the system ...

We investigate dynamics of semiquantal spin systems in which quantum bits are attached to classically and possibly stochastically moving classical particles. The interaction between the quantum bits takes place when the respective classical particles get close to each other in space. We find that wi...

Fine-structure intervals between n=17 Rydberg states of magnesium with 6≤L≥11 were measured using the resonant excitation Stark ionization spectroscopy technique. Comparing the measured intervals with the long-range polarization model determines the dipole and quadrupole polarizabilities of ...

We employed the Schwinger multichannel method to compute elastic cross sections for low-energy electron collisions with propane (C₃H₈) . The calculations are carried out within the static-exchange and static-exchange plus polarization approximations and covered the energy range from 0 to 15 eV. The...

We present measurements of total cross sections for 1 to 30 eV positrons scattered by uracil molecules. The measurements are done using a beam transmission technique on a setup adjusted to accommodate the nature of uracil and we discuss possibilities of future experiments studying positron interacti...

We investigate magnetic Feshbach resonances in two different ultracold K-Rb mixtures. Information on the ³⁹K-⁸⁷Rb isotopic pair is combined with preexisting observations of resonance patterns for ⁴⁰K-⁸⁷Rb . Interisotope resonance spectroscopy improves significantly our near-threshold model for sc...

The isotopically mixed hydrogen molecular ion HD⁺ was investigated in intense pulsed laser fields with high, i.e., vibrational resolution of the fragments. An ion beam of HD⁺ with a translational energy of 11.1 keV was exposed to femtosecond laser pulses (100 fs) of intensities in the range from...

We investigate Bose-Einstein condensation for interacting bosons at zero and nonzero temperature. Functional renormalization provides us with a consistent method to compute the effect of fluctuations beyond the Bogoliubov approximation. For three-dimensional dilute gases, we find an upper bound on t...

In this paper we study the density noise correlations of the two component Fermi gas in optical lattices. Three different types of phases, the BCS state (Bardeen, Cooper, and Schieffer), the FFLO state (Fulde, Ferrel, Larkin, and Ovchinnikov), and the BP (breach pair) state are considered. We show h...

The effect of spontaneously generated coherence (SGC) on spontaneous emission and dynamical evolution of a microwave-driven four-level atomic system is studied. Interesting phenomena due to SGC, such as spectral-line narrowing, spectra-line enhancement, spectral-line suppression, and fluorescence qu...

Twin entangled beams produced by single-pass parametric down-conversion (PDC) offer the opportunity to detect weak amount of absorption with an improved sensitivity with respect to standard techniques which make use of classical light sources. We propose a differential measurement scheme which explo...

A theoretical and experimental study of multimode operation regimes in quantum cascade lasers (QCLs) is presented. It is shown that the fast gain recovery of QCLs promotes two multimode regimes: One is spatial hole burning (SHB) and the other one is related to the Risken-Nummedal-Graham-Haken instab...

We present a general quasimode formalism for the quantum treatment of quantum-dot–photon dynamics in coupled-cavity systems in photonic-crystal slabs. The coupled-cavity systems are characterized by a large number of discrete lossy nonorthogonal quasimodes that can be obtained using a combination ...

In a recent paper [D. Li, X. Li, H. Huang, and X. Li, Phys. Rev. A 76, 032304 (2007)], Li proposed the definition of the residual entanglement for general n qubits by means of the stochastic local operations and classical communication. Here we argue that their definition is not suitable for the ...

In D. Li, X. Li, H. Huang, and X. Li [Phys. Rev. A 76, 032304 (2007)], we defined the residual entanglement for odd n qubits. In this reply, we improve the definition by averaging the original residual entanglement with respect to each qubit, which makes the defined quantity invariant under any pe...

It is a well known fact that the presence of material bodies in the vicinity of an atom affects its interaction with the always present quantized electromagnetic field. In this paper, we focus on how the spontaneous emission rate of a given excited atom is altered when this atom is placed inside a perfectly conducting wedge. We begin by briefly presenting the formalism on which our calculations are founded, proceeding then to a long but straightforward calculation of the transition rate. We present results for a general atom but, for the sake of simplicity, we narrow them down to an effective two-level system in our numerical investigations. The oscillatory pattern for the spontaneous emission rate of the atom as we vary its relative position to the wedge as well as the phenomenon of suppression are shown in a couple of graphs.

In this paper we discuss a new type of 4-dimensional representation of the braid group. The matrices of braid operations are constructed by q-deformation of Hamiltonians. One is the Dirac Hamiltonian for free electron with mass m, the other, which we find, is related to the Bogoliubov Hamiltonian for quasiparticles in 3He-B with the same free energy and mass being m/2. In the process, we choose the free q-deformation parameter as a special value in order to be consistent with the anyon description for fractional quantum Hall effect with n = 1/2.

We consider macroscopic, mesoscopic and `S-scopic' quantum superpositions of eigenstates of an observable, and develop some signatures for their existence. We define the extent, or size S of a superposition, with respect to an observable [^x], as being the range of outcomes of [^x] predicted by that superposition. Such superpositions are referred to as generalized S-scopic superpositions to distinguish them from the extreme superpositions that superpose only the two states that have a difference S in their prediction for the observable. We also consider generalized S-scopic superpositions of coherent states. We explore the constraints that are placed on the statistics if we suppose a system to be described by mixtures of superpositions that are restricted in size. In this way we arrive at experimental criteria that are sufficient to deduce the existence of a generalized S-scopic superposition. The signatures developed are useful where one is able to demonstrate a degree of squeezing. We also discuss how the signatures enable a new type of Einstein-Podolsky-Rosen gedanken experiment.

In the last few years there has been a lot of interest in quantum repeater protocols using only atomic ensembles and linear optics. Here we show that the local generation of high-fidelity entangled pairs of atomic excitations, in combination with the use of two-photon detections for long-distance entanglement generation, permits the implementation of a very attractive quantum repeater protocol. Such a repeater is robust with respect to phase fluctuations in the transmission channels, and at the same time achieves higher entanglement generation rates than other protocols using the same ingredients. We propose an efficient method of generating high-fidelity entangled pairs locally, based on the partial readout of the ensemble-based memories. We also discuss the experimental implementation of the proposed protocol.

We propose a novel protocol for perfect quantum state transfer that is resilient to a broad class of realistic experimental imperfections, including noise sources that could be modelled either as independent Markovian baths or as certain forms of spatially correlated environments. We highlight interesting connections between the fidelity of state transfer and quantum stochastic resonance effects. The scheme is flexible enough to act as an effective entangling gate for the generation of genuine multipartite entanglement in a control-limited setting. Possible experimental implementations using superconducting qubits are also briefly discussed.

The Lamb shift of a hydrogen atom due to the surface plasmon polariton (SPP) modes is calculated and we observe both band edge and surface enhancement. The atom sits inside a thin metal slab which is sandwiched by two semi-infinite dielectrics. The SPP dispersion relation shows a band gap if the two dielectrics have different dielectric constants. We find the magnitude of the 2P1/2 level shift increases rapidly when the level separation is close to the high band edge. But the low band edge enhancement can be overwhelmed by the decreasing trend of the shift. If the atom is placed close to either surface or if the slab is narrow, all the level shifts would be large because of the surface enhancement. An interesting feature is that the 2P1/2 level shift can be larger than the 2S level shift due to the nonisotropic fields.

We have performed high-accuracy quantum mechanical calculations for the three lowest S-states of the beryllium ion (9Be+). The nonrelativistic part of the calculations was done with the variational approach and explicitly included the nuclear motion (i.e. the finite-nuclear-mass approach). The nonrelativistic wave functions were expanded in terms of explicitly correlated Gaussian functions. These nonrelativistic functions were subsequently used to calculate the leading a2 relativistic corrections (a = 1/c) and the a3 and a4 QED (Quantum Electrodynamics) corrections. In the a4 QED correction we only accounted for its dominant component typically contributing about 80% of the correction. With those the present results are the most accurate ever obtained for 9Be+. They also agree with the experimentally measured transitions within less than 0.1 cm-1.

This paper discusses the possibility of developing a frequency standard using molecular vibrational transition frequencies, which are useful in optical communications. Cold molecules ( < 300 mK) are trapped by microwave or infrared laser light, whose frequency is chosen so that the Stark shift on the transition frequency is significantly reduced. Microwave trapping is much more advantageous than infrared trapping for measuring the vibrational transition frequency to within an uncertainty of 10-11.

We present an accurate computation of the g-factors of the hyperfine states of the hydrogen molecular ion H2+. The results are in good agreement with previous experiments, and can be tested further by rf spectroscopy. Their implication for high-precision two-photon vibrational spectroscopy of H2+ is also discussed. It is found that the most intense hyperfine components of two-photon lines benefit from a very small Zeeman splitting.

The Li (i = 1-3) subshell x-ray spectra for the 52Te, 53I, 55Cs, 56Ba, and 57La elements excited by the Mn K #61537; ( #61472; #61472;= 5.888 keV and #61472;= 5.899 keV) x rays have been investigated using the 55Fe radioisotope in conjunction with a Cr absorber. Low-energy Ge detector was used to measure the L x rays at an emission angle, #61561; = 126o, where the second-order Legendre polynomial term, P2 (cos #61561;), associated with the angular distribution is annulled. In case of the 56Ba and 57La elements, alignment of the L3 subshell vacancy states was investigated through angular distribution measurements of the emitted L3 subshell x-rays. The L #61537;1,2 and L #61538;2,15 x-ray groups are observed to be nearly isotropic, while the data for the pure Ll (L3-M1) x-ray emission is indicative of small anisotropic trend though within experimental error. The integral x-ray fluorescence cross sections are deduced and interpreted in terms of Li subshell photoionization cross sections, the fluorescence and Coster-Kronig yields, and the x-ray emission rates. The L2 subshell x-ray cross sections for 57La measured using targets of lanthanum (III) fluoride and dilanthanum (III) trioxide are found to be unusually higher. The enhancement is observed due to contribution of the L2 subshell radiative resonant Raman scattering (RRS) of the Mn K #61537; x rays having energy around the L2 subshell binding energy of 57La in these compounds. Also, the observed enhancement of the L3 subshell x-ray cross sections in 57La is suggestive of the intrashell vacancy transfer via the L2-L3 Coster-Kronig RRS transitions. The L2 subshell total RRS cross sections in 57La have been deduced from the present measured attenuation coefficients for the Mn K #61537; x rays in La2O3 and LaF3. The L2 subshell radiative and total RRS cross sections in 57La using LaF3 are higher by  30 contribution of processes predicted in the framework of Mozouchi’s four-band model involving the inner subshells along with the valence and conduction bands of these wide band gap insulator compounds are likely account for the observed results. The L2-subshell radiative and the L2-L3 Coster-Kronig yields, and ratio of the L2-M4 and L2-N4 radiative RRS intensities in both the La compounds are found to be same, and are consistent with the values from the photoexcited vacancy decay. The L2 subshell radiative RRS was also observed to be isotropic.

Harmonic emission from cluster nanoplasmas subject to short intense infrared laser pulses is studied. In a previous publication [M. Kundu et al., 76, 033201 (2007)] we reported particle-in-cell simulation results showing resonant enhancements of low-order harmonics when the Mie plasma frequency of the ionizing and expanding cluster resonates with the respective harmonic frequency. Simultaneously we found that high-order harmonics were barely present in the spectrum, even at high intensities. The current paper is focused on the analytical modeling of the process. We show that dynamical stochasticity owing to nonlinear resonance inhibits the emission of high order harmonics.

Numerical calculations of photodetachment of F- irradiated by a linearly polarized strong, short infrared pulse have been performed by evaluating the photoelectron ejection probability in the framework of a Keldysh type approach modified to account for the temporal behavior of the pulse. The results of the calculations are in good agreement with measurements of energy spectra recently appeared in literature, and show features that may be explained in terms of quantum interferences in time domain.

We present the computation of two-photon transition spectra between ro-vibrational states of the H2+ molecular ion, including the effects of hyperfine structure and excitation polarization. The reduced two-photon matrix elements are obtained by means of a variational method. We discuss the implications of our results for high-resolution spectroscopy of H2+.

We study the spectral profile of Rayleigh scattered light from molecular species trapped in optical lattices created by strong fields in the 1016 Wm-2 range. We show that, for lattices with well depths on the order of 100 K, the motional sidebands imparted on spectra are shifted from the central Dicke-narrowed Rayleigh peak by hundreds of MHz. Our calculations for these short duration (30 ns) lattices show that these spectral features appear even in room temperature gases suggesting a new technique for measuring gas composition based on the frequency offset of the sidebands. Finally, we study the role of field-induced molecular alignment within the lattice and calculate its effect on the shape and position of the sidebands.

We introduce a novel type of time-averaged trap, in which the internal state of the atoms is rapidly modulated to modify magnetic trapping potentials. In our experiment, fast radiofrequency (rf) linear sweeps flip the spin of atoms at a fast rate, which averages out magnetic forces. We use this procedure to optimize the accumulation of metastable chomium atoms into an optical dipole trap from a Magneto-Optical Trap. The potential experienced by the metastable atoms is identical to the bare optical dipole potential, so that this procedure allows for trapping all magnetic sublevels, hence increasing by up to 80 percent the final number of accumulated atoms.

We analyse the rotation of bright solitary waves formed of atomic Bose-Einstein condensates with attractive atomic interactions. By employing a variational technique and assuming an irrotational quadrupolar flow field, we map out the variational solutions in the rotating frame. In particular, we show that rotation has a considerable stabilising effect on the system, significantly raising the critical threshold for collapse of the bright solitary waves.

We consider a system of quantum degenerate spin polarized fermions in a harmonic trap at zero temperature, interacting via dipole-dipole forces. We introduce a variational Wigner function to describe the deformation and compression of the Fermi gas in phase space and use it to examine the stability of the system. We emphasize the important roles played by the Fock exchange term of the dipolar interaction which results in a non-spherical Fermi surface.

We show that a dynamically evolving two-mode Bose-Einstein condensate (TBEC) with an adiabatic, time-varying Raman coupling maps exactly onto a Ramsey interferometer that includes a nonlinear medium. Assuming a realistic quantum state for the TBEC that has been achieved experimantally, we find that the measurement uncertainty of the "path-difference" phase shift scales as the standard quantum limit (1/ÖN) where N is the number of atoms, while that for the interatomic scattering strength scales as 1/N7/5, overcoming the conventional Heisenberg limit of 1/N.

The equation of state of the partially polarized two component Fermi gas at zero temperature in the unitary limit is computed by ab initio auxiliary field Monte Carlo method. From this, we obtain the critical ratio of the chemical potentials m¯/m­ at the phase transitions. The value of m¯/m­ at the transition between the fully paired superfluid and the partially polarized phases is 0.11 while the critical value at the phase transition between the partially polarized phase and the fully polarized normal fluid is -0.59. We also determine the radial boundaries of the phase transitions of the Fermi gas in the harmonic trap as function of the total polarization. We find that beyond the critical polarization 0.65, the fully paired superfluid core disappears in the trapped Fermi gas.

The paper discusses the master equation approach to derivation of the Esaki-Tsu equation for drift current. It is shown that the relaxation term in the master equation can be identified by measuring the velocity distribution of the carriers. We also show that the standard form of the relaxation term, used earlier to derive Esaki-Tsu equation, predicts unphysical velocity distribution and suggest a more elaborated relaxation term, which is argued to correctly capture the effect of bosonic bath in experiments on atomic current in optical lattices.

We present measurements of the binding energies of 6Li p-wave Feshbach molecules formed in combinations of the \ketF = 1/2, mF = +1/2 (\ket1) and \ketF = 1/2, mF = -1/2 (\ket2) states. The binding energies scale linearly with magnetic field detuning for all three resonances. The relative molecular magnetic moments are found to be 113 ±7 mK/G, 111 ±6 mK/G and 118 ±8 mK/G for the \ket1-\ket1, \ket1-\ket2 and \ket2-\ket2 resonances, respectively, in good agreement with theoretical predictions. Closed channel amplitudes and the size of the p-wave molecules are obtained theoretically from full closed-coupled calculations.

We show that the application of atom interferometry techniques to the internal, i.e. rotational-vibrational states of molecules provides a new tool for ultra-high precision tests of fundamental physics. The measurement principle is based on the fact, that the electronic structure of molecules is not spherically symmetric. A diatomic quantum sensor can hence distinguish between the direction along its internuclear axis and the two orthogonal directions and is therefore direction sensitive. As an example we show how a molecular rotational-vibrational quantum interferometer based on the hydrogen deuteride molecular ion () may be used to detect gravitational waves. We show that a monochromatic gravitational wave of dimensionless amplitude h=10-19 will cause a frequency shift of the order of 30 mHz between appropriately prepared quantum states, a frequency difference likely to be detectable with the next generation atom interferometers in 1 s.

We show that a few-cycle pulse launched in a quadratic medium may result in a half-cycle soliton in the form of an single hump, with no oscillating tail. The analysis involves the derivation of a Korteweg-de Vries (KdV) equation from both a classical and a quantum mechanical simple models of matter-radiation interaction. The sign of the electric field in the half-cycle KdV soliton is fully determined by the properties of the material, which definitely breaks the phase invariance.

Here we show how to generate a dark two-mode squeezed state of a trapped ion, employing a three-level ion in a V configuration with a strong decay of the excited states. The degree of squeezing can be manipulated by choosing the intensity of the driving fields. Our scheme is robust against the usual dissipation mechanism and could be implemented with present-day technology. The validity of the approximations employed in this work was tested by numerical calculations, which agreed completely with the analytical solutions.