Evgeny A. Shapiro

Precise Control of Molecular Dynamics with a Femtosecond Frequency Comb

We present a general and highly efficient scheme for performing narrow-band Raman transitions between molecular vibrational levels using a coherent train of weak pump-dump pairs of shaped ultrashort pulses. The use of weak pulses permits an analytic description within the framework of coherent control in the perturbative regime, while coherent accumulation of many pulse pairs enables near unity transfer efficiency with a high spectral selectivity, thus forming a powerful combination of pump-dump control schemes and the precision of the frequency comb. Simulations verify the feasibility and robustness of this concept, with the aim to form deeply bound, ultracold molecules.

Piecewise Adiabatic Population Transfer in a Molecule via a Wave Packet

We propose a class of schemes for robust population transfer between quantum states that utilize trains of coherent pulses, thus forming a generalized adiabatic passage via a wave packet. We study piecewise stimulated Raman adiabatic passage with pulse-to-pulse amplitude variation, and piecewise chirped Raman passage with pulse-to-pulse phase variation, implemented with an optical frequency comb. In the context of production of ultracold ground-state molecules, we show that with almost no knowledge of the excited potential, robust high-efficiency transfer is possible.

Population transfer between two quantum states by piecewise chirping of femtosecond pulses: theory and experiment.

We propose and experimentally demonstrate the method of population transfer by piecewise adiabatic passage between two quantum states. Coherent excitation of a two-level system with a train of ultrashort laser pulses is shown to reproduce the effect of an adiabatic passage, conventionally achieved with a single frequency-chirped pulse. By properly adjusting the amplitudes and phases of the pulses in the excitation pulse train, we achieve complete and robust population transfer to the target state. The piecewise nature of the process suggests a possibility for the selective population transfer in complex quantum systems.

Photoassociation adiabatic passage of ultracold Rb atoms to form ultracold Rb_{2} molecules

We theoretically explore photoassociation by adiabatic passage of two colliding cold

Complete transfer of populations from a single state to a preselected superposition of states using piecewise adiabatic passage: Experiment

^{85}\mathrm{Rb}

Enhancing strong-field-induced molecular vibration with femtosecond pulse shaping

atoms in an atomic trap to form an ultracold

Electromagnetically induced transparency spectroscopy

{\mathrm{Rb}}_{2}

Coherent rovibrational revivals in a thermal molecular ensemble

molecule. We consider the incoherent thermal nature of the scattering process in a trap and show that coherent manipulations of the atomic ensemble, such as adiabatic passage, are feasible if performed within the coherence time window dictated by the temperature, which is relatively long for cold atoms. We show that a sequence of

Interference spectroscopy with coherent anti-Stokes Raman scattering of noisy broadband pulses

\ensuremath{\sim}2\ifmmode\times\else\texttimes\fi{}{10}^{7}

Negative refraction and photonic-crystal optics in a cold gas

pulses of moderate intensities, each lasting