We propose a practical way of spatially separating a ("racemic") mixture of left-handed (L) and right-handed (R) chiral molecules using optically induced forces. The enantioselectivity of the method emanates from the sign difference between the n<-->m electric-dipole matrix elements of enantiomers of opposite handedness, and the, uniquely chiral, "cyclic adiabatic passage" laser configuration. The combination of these two factors is shown to cause considerable differences in the magnitude and direction of the optically induced forces as felt by enantiomers of opposite handedness. Two arrangements, tested by performing quantum wave packet propagation and classical trajectories, are suggested. Both arrangements involve the intracavity interaction of the racemic mixture with three, partially overlapping, cw laser beams. The first arrangement is composed of trapped molecules at 1 mK interacting with standing wave lasers. The second configuration uses a tightly skimmed molecular beam of a racemic mixture, forming one arm of a four-sided cavity, intersecting at a small angle the three laser beams.

We have demonstrated a general framework for realizing and modulating perpendicular magnetic anisotropy in a rare-earth-element and heavy-metal -free material system. Using GaAs(001)/Fe(001) template, we have developed a synthesis scheme to produce epitaxial body center tetragonal Fe-N with (001) texture. By varying the N doping concentration, the crystal tetragonality (c/a) can be tuned in a relatively wide range. It is found that the Fe-N layer developed a strong perpendicular magnetic crystalline anisotropy (MCA) as it approaches the iron nitride interstitial solubility limit. Further annealing process significantly improves the MCA due to the formation of chemically ordered Fe 16 N 2 . In addition to realize an MCA up to 10 7 erg/cm 3 , the spin polarization ratio (P~0.52), as probed directly by a Point Contact Andreev Reflection (PCAR) method, even shows a moderate increase in comparison with normal metal Fe (P~0.45). These combined properties make this material system a promising candidate for applications in spintronic devices and also potential rare-earth-element free magnets.

The decay of highly excited states of xenon after absorption of extreme ultraviolet light is directly tracked via attosecond transient absorption spectroscopy using a time-delayed near-infrared perturbing pulse. The lifetimes of the autoionizing 5s5p 6 6p and 5s5p 6 7p channels are determined to be (21.9 ± 1.3) fs and (48.4 ± 5.0) fs, respectively. The observed values support lifetime estimates obtained by traditional linewidth measurements. The experiment additionally obtains the temporal evolution of the decay as a function of energy detuning from the resonance center, and a quantum mechanical formalism is introduced that correctly accounts for the observed energy dependence.

We used extreme ultraviolet (XUV) transient absorption spectroscopy to study the autoionizing Rydberg states of oxygen in electronically and vibrationally resolved fashion. XUV pulse initiates molecular polarization and near infrared (NIR) pulse perturbs its evolution. Transient absorption spectra show positive optical density (OD) change in the case of nsσ g and ndπ g autoionizing states of oxygen and negative OD change for ndσ g states. Multiconfiguration time-dependent HartreeFock (MCTDHF) calculations are used to simulate the transient absorption and the resulting spectra and temporal evolution agree with experimental observations. We model the effect of nearinfrared (NIR) perturbation on molecular polarization and find that the laser induced phase shift model agrees with the experimental and MCTDHF results, while the laser induced attenuation model does not. We relate the electronic state symmetry dependent sign of the OD change to the Fano parameters of the static absorption line shapes.

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