Zitterbewegung and Klein-tunneling phenomena for transient quantum waves

• URL: http://arxiv.org/abs/2003.04417v1
• Date: Mon, 9 Mar 2020 21:27:02 GMT
• Title: Zitterbewegung and Klein-tunneling phenomena for transient quantum waves
• Authors: Fernando Nieto-Guadarrama and Jorge Villavicencio
• Abstract summary: We show that the Zitterbewegung effect manifests itself as a series of quantum beats of the particle density in the long-time limit. We also find a time-domain where the particle density of the point source is governed by the propagation of a main wavefront. The relative positions of these wavefronts are used to investigate the time-delay of quantum waves in the Klein-tunneling regime.
• Score: 77.34726150561087
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We explore the dynamics of relativistic quantum waves in a potential step by using an exact solution to the Klein-Gordon equation with a point source initial condition. We show that in both the propagation, and Klein-tunneling regimes, the Zitterbewegung effect manifests itself as a series of quantum beats of the particle density in the long-time limit. We demonstrate that the beating phenomenon is characterized by the Zitterbewegung frequency, and that the amplitude of these oscillations decays as $t^{-3/2}$. We show that beating effect also manifests itself in the free Klein-Gordon and Dirac equations within a quantum shutter setup, which involve the dynamics of cut-off quantum states. We also find a time-domain where the particle density of the point source is governed by the propagation of a main wavefront, exhibiting an oscillating pattern similar to the diffraction in time phenomenon observed in non-relativistic systems. The relative positions of these wavefronts are used to investigate the time-delay of quantum waves in the Klein-tunneling regime. We show that, depending on the energy difference, ${\cal E}$, between the source and the potential step, the time-delay can be positive, negative or zero. The latter case corresponds to a super-Klein-tunneling configuration, where ${\cal E}$ equals to half the energy of the potential step.

Related papers

• Phase modulation of directed transport, energy diffusion and quantum scrambling in a Floquet non-Hermitian system [3.250943494257319]
  We investigate both theoretically and numerically the wavepacket's dynamics in momentum space for a Floquet non-Hermitian system. We have deduced the exact expression of a time-evolving wavepacket under the condition of quantum resonance.
  arXiv  Detail & Related papers  (2023-12-13T11:56:50Z)
• Particle motion associated with wave function density gradients [0.0]
  We study the quantum mechanical motion of massive particles in a system of two coupled waveguide potentials. Regions of gain and loss, as described by imaginary potentials, are shown to speed up the motion of particles.
  arXiv  Detail & Related papers  (2022-12-22T10:02:47Z)
• Out-of-time-order correlator in the quantum Rabi model [62.997667081978825]
  We show that out-of-time-order correlator derived from the Loschmidt echo signal quickly saturates in the normal phase. We show that the effective time-averaged dimension of the quantum Rabi system can be large compared to the spin system size.
  arXiv  Detail & Related papers  (2022-01-17T10:56:57Z)
• Visualizing spinon Fermi surfaces with time-dependent spectroscopy [62.997667081978825]
  We propose applying time-dependent photo-emission spectroscopy, an established tool in solid state systems, in cold atom quantum simulators. We show in exact diagonalization simulations of the one-dimensional $t-J$ model that the spinons start to populate previously unoccupied states in an effective band structure. The dependence of the spectral function on the time after the pump pulse reveals collective interactions among spinons.
  arXiv  Detail & Related papers  (2021-05-27T18:00:02Z)
• Continuous-time dynamics and error scaling of noisy highly-entangling quantum circuits [58.720142291102135]
  We simulate a noisy quantum Fourier transform processor with up to 21 qubits. We take into account microscopic dissipative processes rather than relying on digital error models. We show that depending on the dissipative mechanisms at play, the choice of input state has a strong impact on the performance of the quantum algorithm.
  arXiv  Detail & Related papers  (2021-02-08T14:55:44Z)
• Bloch-Landau-Zener dynamics induced by a synthetic field in a photonic quantum walk [52.77024349608834]
  We realize a photonic quantum walk in the presence of a synthetic gauge field. We investigate intriguing system dynamics characterized by the interplay between Bloch oscillations and Landau-Zener transitions.
  arXiv  Detail & Related papers  (2020-11-11T16:35:41Z)
• Bloch-like super-oscillations and unidirectional motion of phase driven quantum walkers [0.0]
  We study the dynamics of a quantum walker simultaneously subjected to time-independent and -dependent phases. We show that the average drift velocity can be well described within a continuous-time analogous model.
  arXiv  Detail & Related papers  (2020-08-15T12:19:05Z)
• Theory of waveguide-QED with moving emitters [68.8204255655161]
  We study a system composed by a waveguide and a moving quantum emitter in the single excitation subspace. We first characterize single-photon scattering off a single moving quantum emitter, showing both nonreciprocal transmission and recoil-induced reduction of the quantum emitter motional energy.
  arXiv  Detail & Related papers  (2020-03-20T12:14:10Z)
• A mechanical analog of quantum bradyons and tachyons [0.0]
  We present an analog of a quantum wave-particle duality: a vibrating string threaded through a freely moving bead or masslet' For small string amplitudes, the particle movement is governed by a set of non-linear dynamical equations. Subsonic and supersonic particles can fall into a quantum regime as with the slower-than-light bradyons and hypothetical, faster-than-light tachyons of particle physics.
  arXiv  Detail & Related papers  (2020-02-19T12:56:52Z)
• Driving Quantum Correlated Atom-Pairs from a Bose-Einstein Condensate [0.0]
  We investigate one such control protocol that demonstrates the resonant amplification of quasimomentum pairs from a Bose-Einstein condensate. A classical external field that excites pairs of particles with the same energy but opposite momenta is reminiscent of the coherently-driven nonlinearity in a parametric amplifier crystal.
  arXiv  Detail & Related papers  (2020-01-08T00:11:26Z)

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.