SEARCH FOR A SUPERFLUID PHASE OF PARAHYDROGEN: EXPLORING THE EFFECT OF CONFINEMENT

• Author / Creator

  Omiyinka, Tokunbo P

• The first part of this thesis theoretically studies the low temperature physics of parahydrogen (p-H2) confined in cylindrical channels of diameter of the order of 1 nm, based on the Continuous-Space Worm Algorithm quantum Monte Carlo simulations. On varying the attractive strength of the wall of the cylindrical pore, as well as its diameter, the equilibrium phase evolves from a single quasi-one-dimensional (1D) channel along the axis, to a concentric cylindrical shell. It is found that the quasi-1D system retains a strong propensity to crystallization, even though on weakly attractive substrates quantum fluctuations reduce somewhat such a tendency compared to the purely 1D system. No evidence of a topologically protected superfluid phase (in the Luttinger sense) is observed. Secondly, this research work explores the possibility of existence of a metastable superfluid phase of p-H2 in the low temperature limit. It was found that any possible occurence of superfluidity in supercooled p-H2 would have to be at a much lower temperature than 2 K. Furthermore, this thesis investigates how different p-H2 is from a Bose system that possesses a metastable superfluid phase despite having a crystalline ground state. Finally, study is also carried out to elucidate the inherent distinctions between an hypothetical metastable p-H2 liquid and a metastable 4He liquid, underscoring the essential origin of the almost conclusive absence of superfluidity in any phase of p-H2. Extensive discussions are also provided on the implications of this work for the possible existence of a bulk superfluid phase of parahydrogen.

• Subjects / Keywords

  • MEGABAR PRESSURE
  • NANOSCALE CONFINEMENT
  • PARAHYDROGEN
  • WORM ALGORITHM
  • SILVERA GOLDMAN
  • PAIR CORRELATION FUNCTION
  • MODIFIED MORALDI POTENTIAL
  • LUTTINGER LIQUID THEORY
  • PAIR POTENTIAL
  • SUPERFUIDITY
  • LUTTINGER PARAMETER

• Graduation date

  Fall 2016

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3HH6CH07

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.