Coherent superposition of M-states in a single rovibrational level of H2 by Stark-induced adiabatic Raman passage
Abstract
We prepare an ensemble of isolated rovibrationally excited (v = 1, J = 2) H2 molecules in a phase-locked superposition of magnetic sublevels M using Stark-induced adiabatic Raman passage with linearly polarized single-mode pump (at 532 nm, ∼6 ns pulse duration, 200 mJ/pulse) and Stokes (699 nm, ∼4 ns pulse duration, 20 mJ/pulse) laser excitation. A biaxial superposition state, given by $| {\psi (t)}\rangle = 1/\sqrt {(2)} [ | {v=1,J = 2,M = - 2} \rangle - | {v=1,J = 2,M = + 2} \rangle ]$|ψ(t)⟩=1/(2)[|v=1,J=2,M=−2⟩−|v=1,J=2,M=+2⟩], is prepared with linearly but cross-polarized pump and Stokes laser pulses copropagating along the quantization z-axis. The degree of phase coherence is measured by using the O(2) line of the H2 E,F-X (0,1) band via 2 + 1 resonance enhanced multiphoton ionization (REMPI) at 210.8 nm by recording interference fringes in the REMPI signal in a time-of-flight mass spectrometer as the direction of the UV laser polarization is rotated using a half-wave plate. Nearly 60% population transfer from H2 (v = 0, J = 0) ground state to the superposition state in H2 (v = 1, J = 2) is measured from the depletion of the Q(0) line of the E,F-X (0,0) band as the Stokes frequency is tuned across the (v = 0, J = 0) → (v = 1, J = 2) Raman resonance.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 18, 2014
- Source ID
- 10.1063/1.4865131
Entities
People
- Nandini Mukherjee
- Richard Zare
- Wenrui Dong
Organizations
- Army Research Office
- Stanford University