Scattering of a composite quasiparticle by an impurity on a lattice
arXiv:1701.04899 · doi:10.1103/PhysRevB.96.054307
Abstract
We study scattering of a composite quasiparticle, which possesses a degree of freedom corresponding to relative separation between two bound excitations, by a delta-like impurity potential on a one-dimensional discrete lattice. Firstly, we show that, due to specific properties of their dispersion, lattice excitations bind to impurities with both negative and positive potentials. We demonstrate that the finite size of the composite excitation leads to formation of multiple excitation-impurity bound states. The number and the degree of localization of these bound states depend on the signs and relative magnitudes of the impurity potential and the binding strength of two quasiparticles. We also report the existence of excitation-impurity bound states whose energies are located in the continuum band. Secondly, we study a change in the entanglement between the centre of mass and relative coordinate degrees of freedom of a biexciton wave packet during single impurity scattering and decoherence caused by it. For a composite quasiparticle on a lattice, the entanglement between its relative and centre of mass coordinate degrees of freedom arises naturally due to inseparability of the two-particle Hamiltonian. One of the main focuses of our study is to investigate how this inseparability affects the creation of the biexciton-impurity bound states and the entanglement dynamics.
arXiv comment15 pages, 8 figures, accepted by PRB
References in corpus (22)
- Experimental long-lived entanglement of two macroscopic objects
- Repulsively bound atom pairs in an optical lattice
- Strongly Correlated Two-Photon Transport in One-Dimensional Waveguide Coupled to A Two-Level System
- Tunable Superfluidity and Quantum Magnetism with Ultracold Polar Molecules
- Universal decoherence due to gravitational time dilation
- Strongly-correlated multi-particle transport in one-dimension through a quantum impurity: an outline of exact and complete solutions
- Creation of a low-entropy quantum gas of polar molecules in an optical lattice
- Input-Output Formalism for Few-Photon Transport: A Systematic Treatment Beyond Two Photons
- Scattering of two photons from two distant qubits: Exact solution
- Two-body physics in the Su-Schrieffer-Heeger model
- Bound States in the Continuum Realized in the One-Dimensional Two-Particle Hubbard Model with an Impurity
- Tunneling of a composite particle: Effects of intrinsic structure
- Tunable disorder in a crystal of cold polar molecules
- Quantum Transparency of Barriers for Structure Particles
- Metastable States of a Coupled Pair on a Repulsive Barrier
- Effects of long-range hopping and interactions on quantum walk in ordered and disordered lattices
- Bound states in the one-dimensional two-particle Hubbard model with an impurity
- Tunable exciton interactions in optical lattices with polar molecules
- Anomalous tunneling of bound pairs in crystal lattices
- Quantum tunneling of a complex systems: effects of finite size and intrinsic structure
- Long-lived resonances at mirrors
- Integrability and weak diffraction in a two-particle Bose-Hubbard model