Understanding chemical reactions in a quantum degenerate gas of polar molecules via complex formation

• URL: http://arxiv.org/abs/2008.05904v1
• Date: Wed, 12 Aug 2020 16:00:11 GMT
• Title: Understanding chemical reactions in a quantum degenerate gas of polar molecules via complex formation
• Authors: Peiru He, Thomas Bilitewski, Chris H. Greene, Ana Maria Rey
• Abstract summary: We develop a simple model of chemical reactions that occur via the formation and decay of molecular complexes. We observe that additional complex-molecule collisions, which manifest as a net three-body molecular interaction could give rise to the additional suppression.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: A recent experiment reported for the first time the preparation of a Fermi degenerate gas of polar molecules and observed a suppression of their chemical reaction rate compared to the one expected from a purely classical treatment. While it was hypothesized that the suppression in the ultracold regime had its roots in the Fermi statistics of the molecules, this argument is inconsistent with the fact that the Fermi pressure should set a lower bound for the chemical reaction rate. Therefore it can not be explained from standard two-body $p$-wave inelastic collisions. Here we develop a simple model of chemical reactions that occur via the formation and decay of molecular complexes. We indeed find that pure two-body molecule losses are unable to explain the observed suppression. Instead we extend our description beyond two-body physics by including effective complex-molecule interactions possible emerging from many-body and effective medium effects at finite densities and in the presence of trapping light. %Under this framework we observe that additional complex-molecule collisions, which manifest as a net three-body molecular interaction could give rise to the additional suppression. Although our effective model is able to quantitatively reproduce recent experimental observations, a detailed understanding of the actual physical mechanism responsible for these higher-order interaction processes is still pending.

Related papers

• The strongly driven Fermi polaron [49.81410781350196]
  Quasiparticles are emergent excitations of matter that underlie much of our understanding of quantum many-body systems. We take advantage of the clean setting of homogeneous quantum gases and fast radio-frequency control to manipulate Fermi polarons. We measure the decay rate and the quasiparticle residue of the driven polaron from the Rabi oscillations between the two internal states.
  arXiv  Detail & Related papers  (2023-08-10T17:59:51Z)
• Efficient Reduction of Casimir Forces by Self-assembled Bio-molecular Thin Films [62.997667081978825]
  Casimir forces, related to London-van der Waals forces, arise if the spectrum of electromagnetic fluctuations is restricted by boundaries. We experimentally investigate the influence of self-assembled molecular bio and organic thin films on the Casimir force between a plate and a sphere. We find that molecular thin films, despite being a mere few nanometers thick, reduce the Casimir force by up to 14%.
  arXiv  Detail & Related papers  (2023-06-28T13:44:07Z)
• Sensing of magnetic field effects in radical-pair reactions using a quantum sensor [50.591267188664666]
  Magnetic field effects (MFE) in certain chemical reactions have been well established in the last five decades. We employ elaborate and realistic models of radical-pairs, considering its coupling to the local spin environment and the sensor. For two model systems, we derive signals of MFE detectable even in the weak coupling regime between radical-pair and NV quantum sensor.
  arXiv  Detail & Related papers  (2022-09-28T12:56:15Z)
• Dynamic of Single Molecules in Collective Light-Matter States from First Principles [0.0]
  coherent interaction of a large collection of molecules with a common photonic mode results in strong light-matter coupling. I introduce a simple approach to capture the collective nature while retaining the full ab initio representation of single molecules. I illustrate that the influence of collective strong coupling on chemical reactions features a nontrivial dependence on the number of emitters.
  arXiv  Detail & Related papers  (2022-04-04T15:58:04Z)
• Electric field dependence of complex-dominated ultracold molecular collisions [0.0]
  We propose a model based on the mixing effect of an electric field on the states of the two diatomic molecules at long-range. We apply our model to collisions of ground-state molecules of endothermic systems.
  arXiv  Detail & Related papers  (2021-09-06T16:59:21Z)
• Relativistic aspects of orbital and magnetic anisotropies in the chemical bonding and structure of lanthanide molecules [60.17174832243075]
  We study the electronic and ro-vibrational states of heavy homonuclear lanthanide Er2 and Tm2 molecules by applying state-of-the-art relativistic methods. We were able to obtain reliable spin-orbit and correlation-induced splittings between the 91 Er2 and 36 Tm2 electronic potentials dissociating to two ground-state atoms.
  arXiv  Detail & Related papers  (2021-07-06T15:34:00Z)
• Collective spontaneous emission of two entangled atoms near an oscillating mirror [50.591267188664666]
  We consider the cooperative spontaneous emission of a system of two identical atoms, interacting with the electromagnetic field in the vacuum state. Using time-dependent theory, we investigate the spectrum of the radiation emitted by the two-atom system. We show that it is modulated in time, and that the presence of the oscillating mirror can enhance or inhibit the decay rate.
  arXiv  Detail & Related papers  (2020-10-07T06:48:20Z)
• Resonant collisional shielding of reactive molecules using electric fields [2.830197032154302]
  We use an external electric field to shift excited collision channels of ultracold molecules into degeneracy with the initial collision channel. Resonant dipolar interactions mix the channels at long range, dramatically altering the intermolecular potential. We realize a long-lived sample of polar molecules in large electric fields.
  arXiv  Detail & Related papers  (2020-09-16T04:24:54Z)
• Dipolar evaporation of reactive molecules to below the Fermi temperature [2.9989215527241453]
  Inelastic losses in molecular collisions have greatly hampered the engineering of low-entropy molecular systems. Here, we use an external electric field along with optical lattice confinement to create a two-dimensional (2D) Fermi gas of spin-polarized potassium-rubidium (KRb) polar molecules. Direct thermalization among the molecules in the trap leads to efficient dipolar cooling, yielding a rapid increase in phase-space density.
  arXiv  Detail & Related papers  (2020-07-23T22:02:59Z)
• Dynamical Strengthening of Covalent and Non-Covalent Molecular Interactions by Nuclear Quantum Effects at Finite Temperature [58.999762016297865]
  Nuclear quantum effects (NQE) tend to generate delocalized molecular dynamics. NQE often enhance electronic interactions and, in turn, can result in dynamical molecular stabilization at finite temperature. Our findings yield new insights into the versatile role of nuclear quantum fluctuations in molecules and materials.
  arXiv  Detail & Related papers  (2020-06-18T14:30:29Z)
• Vibrational quenching of cold molecular ions immersed in their parent gas [0.0]
  We study theoretically the process of vibrational relaxation of an initially weakly bound molecular ion due to collisions with background gas atoms. We find that the inelastic collisions lead predominantly to small changes in the binding energy of the molecular ion.
  arXiv  Detail & Related papers  (2020-03-03T10:12:10Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.