2003/09/30 by Robert E. Zillich, R. E. Zillich, K. Birgitta Whaley +1 · 50 citations
Mathematics · Physics and Astronomy · #Atomic and Subatomic Physics Research #Atomic physics #Cold Atom Physics and Bose-Einstein Condensates #Diffusion Monte Carlo #Excited state #Ground state #Hybrid Monte Carlo #Mathematics #Moment of inertia #Monte Carlo method #Physics #Quantum Monte Carlo #Quantum mechanics #Quantum, superfluid, helium dynamics #Spectral line #Statistics #cond-mat
paper · pdf · doi:10.1103/physrevb.69.104517
published in Physical Review B 69(10) (American Physical Society) · accepted by Phys. Rev. B; changes: included referee suggestions, removed typos, added 10 refs
arxiv created 2003/12/15 · openalex publication_date 2004/03/23 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present calculations of rotational absorption spectra of the molecules HCN and DCN in superfluid 4He, using a combination of the diffusion Monte Carlo method for ground-state properties and an analytic many-body method (correlated basis function theory) for the excited states. Our results agree with the experimentally determined effective moment of inertia which has been obtained from the J=\stackrel\ensuremath→01 spectral transition. The correlated basis function analysis shows that, unlike heavy rotors such as OCS, the J=2 and higher rotational excitations of HCN and DCN have high-enough energy to strongly couple to rotons, leading to large shifts of the lines and accordingly to anomalous large spectroscopic distortion constants, to the possibility of roton-maxon bands, and of secondary peaks in the absorption spectra for J=2 and J=3.