All Publications

  • Coherent Preparation of Highly Vibrating and Rotating D2 Molecules. The journal of physical chemistry letters Perreault, W. E., Zhou, H., Mukherjee, N., Zare, R. N. 2022: 4682-4687


    Highly vibrationally and rotationally excited hydrogen molecules are of immense interest for understanding and modeling the physics and chemistry of the cold interstellar medium. Using a sequence of two Stark-induced adiabatic Raman passages, we demonstrate the preparation of rotationally excited D2 molecules in the fourth excited vibrational level within its ground electronic state. The nearly complete population transfer to the target state is confirmed by observing both the threshold behavior as a function of the laser power and the depletion of the intermediate level. The vibrational excitation reported here opens new possibilities in the study of the much debated four-center reaction between a pair of hydrogen molecules. Additionally, these rovibrationally excited molecules could be potentially used to generate the high-intensity D- ion beams considered essential for D-T thermonuclear fusion by enhancing the cross section for dissociative electron attachment by 5 orders of magnitude compared to that of the ground state.

    View details for DOI 10.1021/acs.jpclett.2c01209

    View details for PubMedID 35605182

  • Coherent Preparation of Highly Vibrating and Rotating D-2 Molecules JOURNAL OF PHYSICAL CHEMISTRY LETTERS Perreault, W. E., Zhou, H., Mukherjee, N., Zare, R. N. 2022
  • Anisotropic dynamics of resonant scattering between a pair of cold aligned diatoms. Nature chemistry Zhou, H., Perreault, W. E., Mukherjee, N., Zare, R. N. 2022


    The collision dynamics between a pair of aligned molecules in the presence of a partial-wave resonance provide the most sensitive probe of the long-range anisotropic forces important to chemical reactions. Here we control the collision temperature and geometry to probe the dynamics of cold (1-3K) rotationally inelastic scattering of a pair of optically state-prepared D2 molecules. The collision temperature is manipulated by combining the gating action of laser state preparation and detection with the velocity dispersion of the molecular beam. When the bond axes of both molecules are aligned parallel to the collision velocity, the scattering rate drops by a factor of 3.5 as collision energies >2.1K are removed, suggesting a geometry-dependent resonance. Partial-wave analysis of the measured angular distribution supports a shape resonance within the centrifugal barrier of the l=2 incoming orbital. Our experiment illustrates the strong anisotropy of the quadrupole-quadrupole interaction that controls the dynamics of resonant scattering.

    View details for DOI 10.1038/s41557-022-00926-z

    View details for PubMedID 35501483

  • A Bi-Axial Quantum State That Controls Molecular Collisions Like a Double-Slit Interferometer FRONTIERS IN PHYSICS Perreault, W. E., Zhou, H., Mukherjee, N., Zare, R. N. 2021; 9
  • Shape resonance determined from angular distribution in D2 (v = 2, j = 2) + He → D2 (v = 2, j = 0) + He cold scattering. The Journal of chemical physics Zhou, H. n., Perreault, W. E., Mukherjee, N. n., Zare, R. N. 2021; 154 (10): 104309


    We find an l = 2 shape resonance fingerprinted in the angular distribution of the cold (∼1 K) Δj = 2 rotationally inelastic collision of D2 with He in a single supersonic expansion. The Stark-induced adiabatic Raman passage is used to prepare D2 in the (v = 2, j = 2) rovibrational level with control of the spatial distribution of the bond axis of the molecule by magnetic sublevel selection. We show that the rate of Δj = 2 D2-D2 relaxation is nearly two orders of magnitude weaker than that of D2-He. This suggests that the strong D2-He scattering is caused by an orbiting resonance that is highly sensitive to the shape of the long-range potential.

    View details for DOI 10.1063/5.0045087

    View details for PubMedID 33722006

  • Quantum mechanical double slit for molecular scattering. Science (New York, N.Y.) Zhou, H., Perreault, W. E., Mukherjee, N., Zare, R. N. 2021; 374 (6570): 960-964


    [Figure: see text].

    View details for DOI 10.1126/science.abl4143

    View details for PubMedID 34793222

  • Harnessing the Power of Adiabatic Curve Crossing to Populate the Highly Vibrationally Excited H_{2} (v=7, j=0) Level. Physical review letters Perreault, W. E., Zhou, H. n., Mukherjee, N. n., Zare, R. N. 2020; 124 (16): 163202


    A large ensemble of ∼10^{9} H_{2} (v=7, j=0) molecules is prepared in the collision-free environment of a supersonic beam by transferring nearly the entire H_{2} (v=0, j=0) ground-state population, where v and j are the vibrational and rotational quantum numbers, respectively. This is accomplished by controlling the crossing of the optically dressed adiabatic states using a pair of phase coherent laser pulses. The preparation of highly vibrationally excited H_{2} molecules opens new opportunities to test fundamental physical principles using two loosely bound yet entangled H atoms.

    View details for DOI 10.1103/PhysRevLett.124.163202

    View details for PubMedID 32383909