arXiv subjects

A. D. Kerin

Publications and source records attributed to A. D. Kerin.

5 recordsLinked to original sources

arXiv2023

Effects of Efimov states on quench dynamics in a three-boson trapped system

We investigate the effects of Efimov states on the post-quench dynamics of a system of three identical bosons with contact interactions, in a spherically-symmetric three-dimensional harmonic trap, which undergoes a quench in interaction strength. Using known hyperspherical solutions to the static three-body problem we calculate semi-analytic results for the Ramsey signal and particle separation as functions of time after the system is quenched. We consider the quench from the non-interacting to strongly interacting and vice versa for a variety of possible Efimov state energies.

cond-mat.quant-gas↗

arXiv2022

Energetics of three interacting mass-imbalanced bodies in a three-dimensional spherical harmonic trap

We consider a system of three particles, either three identical bosons or two identical fermions plus an impurity, within a three-dimensional isotropic trap interacting via a contact interaction. Using two approaches, one using an infinite sum of basis states for the wavefunction and the other a closed form wavefunction, we calculate the allowable energy eigenstates of the system as a function of the interaction strength, including the strongly and weakly interacting limits. For the fermionic case this is done while maintaining generality regarding particle masses. We find that the two methods of calculating the spectrum are in excellent agreement in the strongly interacting limit. However the infinite sum approach is unable to uniquely specify the energy of Efimov states, but in the strongly interacting limit there is, to a high degree of accuracy, a correspondence between the three-body parameter required by the boundary condition of the closed form approach and the summation truncation order required by the summation approach. This specification of the energies and wavefunctions forms the basis with which thermodynamic variables such as the virial coefficients or Tan contacts, or dynamic phenomena like quench dynamics can be calculated.

cond-mat.quant-gas↗

arXiv2022

Quench dynamics of mass-imbalanced three-body fermionic systems in a spherical trap

We consider a system of two identical fermions of general mass interacting with a third distinguishable particle via a contact interaction within an isotropic three-dimensional harmonic trap. We calculate time-dependent observables of the system after it is quenched in s-wave scattering length. To do this we use exact closed form mass-imbalanced hyperspherical solutions to the static three-body problem. These exact solutions enable us to calculate two time-dependent observables, the Ramsey signal and particle separation, after the system undergoes a quench from non-interacting to the unitary regime or vice-versa.

cond-mat.quant-gas↗

arXiv2022

Mountain formation by repeated, inhomogeneous crustal failure in a neutron star

The elastic crust of a neutron star fractures repeatedly as it spins down electromagnetically. An idealised, macroscopic model of inhomogeneous crustal failure is presented based on a cellular automaton with nearest-neighbour tectonic interactions involving strain redistribution and thermal dissipation. Predictions are made of the size and waiting-time distributions of failure events, as well as the rate of failure as the star spins down. The last failure event typically occurs when the star spins down to approximately 1% of its birth frequency with implications for rotational glitch activity. Neutron stars are commonly suggested as sources of continuous gravitational waves. The output of the automaton is converted into predictions of the star's mass ellipticity and gravitational wave strain as functions of its age, with implications for future observations with instruments such as the Laser Interferometer Gravitational Wave Observatory (LIGO), the Virgo interferometer, or the Kamioka Gravitational Wave Detector (KAGRA).

astro-ph.HE↗

arXiv2021

Two-body quench dynamics of harmonically trapped interacting particles

We consider the quantum evolution of a pair of interacting atoms in a three dimensional isotropic trap where the interaction strength is quenched from one value to another. Using exact solutions of the static problem we are able to evaluate time-dependent observables such as the overlap between initial and final states and the expectation value of the separation between the two atoms. In the case where the interaction is quenched from the non-interacting regime to the strongly interacting regime, or vice versa, we are able to obtain analytic results. Examining the overlap between the initial and final states we show that when the interaction is quenched from the non-interacting to strongly interacting regimes the early time dependence dynamics are consistent with theoretical work in the single impurity many-body limit. When the system is quenched from the strongly to non-interacting regime we predict large oscillations in the separation between the two atoms, which arises from a logarithmic divergence due to the zero-range nature of the interaction potential.

cond-mat.quant-gas↗