Microcausality and Tunneling Times in Relativistic Quantum Field Theory

• URL: http://arxiv.org/abs/2507.09066v2
• Date: Sat, 19 Jul 2025 17:58:48 GMT
• Title: Microcausality and Tunneling Times in Relativistic Quantum Field Theory
• Authors: Mohammed Alkhateeb, Alex Matzkin,
• Abstract summary: We show that microcausality precludes superluminal tunneling dynamics.<n>We illustrate these results with numerical computations for Dirac fermions and Klein-Gordon bosons.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We show, in the framework of a space-time resolved relativistic quantum field theory approach to tunneling, that microcausality precludes superluminal tunneling dynamics. More specifically in this work dealing with Dirac and Klein-Gordon fields, we first prove that microcausality holds for such fields in the presence of a background potential. We then use this result to show that an intervention performed on a localized region of an initial wave packet subsequently scattering on a potential barrier does not result in any effect outside the light cone emanating from that region. We illustrate these results with numerical computations for Dirac fermions and Klein-Gordon bosons.

Related papers

• Symmetry-protected topology and deconfined solitons in a multi-link $\mathbb{Z}_2$ gauge theory [45.88028371034407]
  We study a $mathbbZ$ lattice gauge theory defined on a multi-graph with links that can be visualized as great circles of a spherical shell.<n>We show that this leads to state-dependent tunneling amplitudes underlying a phenomenon analogous to the Peierls instability.<n>By performining a detailed analysis based on matrix product states, we prove that charge deconfinement emerges as a consequence of charge-fractionalization.
  arXiv  Detail & Related papers  (2026-03-02T22:59:25Z)
• Real-time collisions of fractional charges in a trapped-ion Jackiw-Rebbi field theory [39.146761527401424]
  We study the effect of back-reaction and quantum fluctuations on the coupled dynamics of the full fermion-boson system.<n>Our results reveal how back-reaction and quantum fluctuations modify the stability and real-time evolution of fractionalized fermions.
  arXiv  Detail & Related papers  (2025-12-08T17:34:53Z)
• Entanglement cones and horizons in analogue cosmological production of Dirac fermions [49.1574468325115]
  We study the appearance of fermion condensates for self-interacting Dirac fermions.<n>We show that the combined breakdown of time-reversal symmetry due to the expanding spacetime, and parity due to a pseudo-scalar condensate, manifest through the structure of the light-cone-like propagation of entanglement in this analogue cQFT.
  arXiv  Detail & Related papers  (2025-03-24T22:20:16Z)
• Interacting Dirac fields in an expanding universe: dynamical condensates and particle production [41.94295877935867]
  This work focuses on a self-interacting field theory of Dirac fermions in an expanding Friedmann-Robertson-Walker universe.<n>We study how the non-trivialative condensates arise and, more importantly, how their real-time evolution has an impact on particle production.
  arXiv  Detail & Related papers  (2024-08-12T14:21:25Z)
• Relativistic Quantum Field Theory Approach to Wavepacket Tunneling: Lack of Superluminal Transmission [0.0]
  We prove by linking the QFT property of micro-causality to the wavepacket behavior that the tunneling dynamics is fully causal. In all cases (Klein tunneling or regular tunneling across a standard or a supercritical potential) the transmitted wavepacket remains in the causal envelope of the propagator.
  arXiv  Detail & Related papers  (2024-07-09T18:00:26Z)
• Interacting chiral fermions on the lattice with matrix product operator norms [37.69303106863453]
  We develop a Hamiltonian formalism for simulating interacting chiral fermions on the lattice. The fermion doubling problem is circumvented by constructing a Fock space endowed with a semi-definite norm. We demonstrate that the scaling limit of the free model recovers the chiral fermion field.
  arXiv  Detail & Related papers  (2024-05-16T17:46:12Z)
• Observation of Quantized Klein Tunneling in a Dielectric Resonator Chain [2.7272044728865885]
  We present the first experimental observation of quantized Klein tunneling in a bounded Dirac system. Our results make an important step to realize and understand the particle-hole physics of Klein tunneling in bounded Dirac systems.
  arXiv  Detail & Related papers  (2024-03-04T13:50:47Z)
• The Fermionic Entanglement Entropy and Area Law for the Relativistic Dirac Vacuum State [44.99833362998488]
  We consider the fermionic entanglement entropy for the free Dirac field in a bounded spatial region of Minkowski spacetime. An area law is proven in the limiting cases where the volume tends to infinity and/or the regularization length tends to zero.
  arXiv  Detail & Related papers  (2023-10-05T12:08:03Z)
• Thermal masses and trapped-ion quantum spin models: a self-consistent approach to Yukawa-type interactions in the $λ\!φ^4$ model [44.99833362998488]
  A quantum simulation of magnetism in trapped-ion systems makes use of the crystal vibrations to mediate pairwise interactions between spins. These interactions can be accounted for by a long-wavelength relativistic theory, where the phonons are described by a coarse-grained Klein-Gordon field. We show that thermal effects, which can be controlled by laser cooling, can unveil this flow through the appearance of thermal masses in interacting QFTs.
  arXiv  Detail & Related papers  (2023-05-10T12:59:07Z)
• Fermion production at the boundary of an expanding universe: a cold-atom gravitational analogue [68.8204255655161]
  We study the phenomenon of cosmological particle production of Dirac fermions in a Friedman-Robertson-Walker spacetime. We present a scheme for the quantum simulation of this gravitational analogue by means of ultra-cold atoms in Raman optical lattices.
  arXiv  Detail & Related papers  (2022-12-02T18:28:23Z)
• Experimental Observation of Curved Light-Cones in a Quantum Field Simulator [0.4462475518267084]
  We investigate signal propagation in a quantum field simulator of the Klein-Gordon model. We observe the propagation of correlations along sharp light-cone fronts. We find agreement with theoretical predictions based on curved geodesics of an inhomogeneous metric.
  arXiv  Detail & Related papers  (2022-09-19T15:56:01Z)
• Space-time resolved quantum field approach to Klein tunneling dynamics across a finite barrier [0.0]
  We find that no particle actually tunnels through a finite supercritical barrier, even in the case of resonant tunneling. The transmission is instead mediated by modulations in pair production rates, at each edge of the barrier.
  arXiv  Detail & Related papers  (2022-05-30T14:13:15Z)
• Manipulating Generalized Dirac Cones In Quantum Metasurfaces [68.8204255655161]
  We consider a collection of single quantum emitters arranged in a honeycomb lattice with subwavelength periodicity. We show that introducing uniaxial anisotropy in the lattice results in modified dispersion relations.
  arXiv  Detail & Related papers  (2022-03-21T17:59:58Z)
• Relativistic spin-0 particle in a box: bound states, wavepackets, and the disappearance of the Klein paradox [0.0]
  We show that a method based on a scattering expansion accounts for Klein tunneling and the Klein paradox in deeper wells. In addition, we show how wavepackets can be constructed semi-analytically from the scattering expansion.
  arXiv  Detail & Related papers  (2021-03-11T09:03:48Z)
• Zitterbewegung and Klein-tunneling phenomena for transient quantum waves [77.34726150561087]
  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.
  arXiv  Detail & Related papers  (2020-03-09T21:27:02Z)

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.