Geometric phase effects in the ultracold D + HD $$ \rightarrow $$ D + HD and D + HD $$\leftrightarrow $$ H + D _{2} reactions
The results of accurate quantum reactive scattering calculations for the D + HD(v = 4, j = 0) $$\to $$ D + HD($$v^{\prime} $$, $$j^{\prime} $$), D + HD(v = 4, j = 0) $$\to $$ H + D2($$v^{\prime} $$, $$j^{\prime} $$) and H + D2(v = 4, j = 0) $$\to $$ D + HD($$v^{\prime} $$, $$j^{\prime} $$) reactions are presented for collision energies between $$1\,\mu {\rm{K}}$$ and $$100\,{\rm{K}}$$. The ab initio BKMP2 PES for the ground electronic state of H3 is used and all values of total angular momentum between $J=04$ are included. The general vector potential approach is used to include the geometric phase. The rotationally resolved, vibrationally resolved, and total reaction rate coefficients are reported as a function of collision energy. Rotationally resolved differential cross sections are also reported as a function of collision energy and scattering angle. Large geometric phase effects appear in the ultracold reaction rate coefficients which result in a significant enhancement or suppression of the rate coefficient (up to 3 orders of magnitude) relative to calculations which ignore the geometric phase. The results are interpreted using a new quantum interference mechanism which is unique to ultracold collisions. Significant effects of the geometric phase also appear in the rotationally resolved differential cross sections which lead to a very different oscillatory structure in both energy and scattering angle. Several shape resonances occur in the 1–$$10\,{\rm{K}}$$ energy range and the geometric phase is shown to significantly alter the predicted resonance spectrum. The geometric phase effects and ultracold rate coefficients depend sensitively on the nuclear spin. Furthermore, experimentalists may be able to control the reaction by the selection of a particular nuclear spin state.
 Authors:

^{[1]}
;
^{[2]};
^{[2]}
 Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
 Univ. of Nevada, Las Vegas, NV (United States)
 Publication Date:
 Report Number(s):
 LAUR1625136
Journal ID: ISSN 13672630; TRN: US1701141
 Grant/Contract Number:
 AC5206NA25396; 20140309ER
 Type:
 Published Article
 Journal Name:
 New Journal of Physics
 Additional Journal Information:
 Journal Volume: 18; Journal Issue: 12; Journal ID: ISSN 13672630
 Publisher:
 IOP Publishing
 Research Org:
 Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
 Sponsoring Org:
 USDOE Laboratory Directed Research and Development (LDRD) Program
 Country of Publication:
 United States
 Language:
 English
 Subject:
 74 ATOMIC AND MOLECULAR PHYSICS; Inorganic and Physical Chemistry; Ultracold chemistry, cold molecules, geometric phase
 OSTI Identifier:
 1336493
 Alternate Identifier(s):
 OSTI ID: 1336494; OSTI ID: 1345159