Non-tunnel effect in quantum mechanics

Mohammad Umar, Vibhav Narayan Singh, Bhabani Prasad Mandal

We investigate the tunneling time of a wave packet propagating through a non-Hermitian potential Vr − iVi in space-fractional quantum mechanics. By applying the stationary phase method, we derive a closed-form expression for the tunneling time for this system. This study presents the first investigation of tunneling time at the interplay of non-Hermitian quantum mechanics and space-fractional quantum mechanics. The variation in tunneling time as the system transitions from a real to a complex potential is analyzed. We demonstrate that the tunneling time exhibits a dependence on the barrier width d in the limit d → ∞, showing the absence of the Hartman effect. A particularly striking feature of our findings is the potential manifestation of the Hartman effect for a specific combination of the absorption component Vi and the Levy index α. This behavior arises from the fact that the presence of the absorption component Vi leads to a monotonic increase in tunneling time with barrier thickness, whereas the Levy index α reduces the tunneling time. The interplay of these contrasting influences facilitates the emergence of the Hartman effect under a specific combination of Vi and the fractional parameter α.

Daniel M. Greenberger

Айдана Нұрғали, Айбота Нұрболат

This article provides a comprehensive review of the quantum tunneling effect, one of the most important phenomena in quantum mechanics. According to the laws of classical physics, a particle cannot overcome a potential barrier if it has insufficient energy. However, in quantum mechanics, due to the wave nature of the particle, the probability of penetrating the barrier is non-zero. This work analyzes in detail the theoretical foundations of the tunneling effect, its description via the Schrödinger equation, probability amplitudes, boundary conditions for wave functions, and their physical meaning. Furthermore, the application of this effect in semiconductor physics, nuclear physics, scanning tunneling microscopy, and nanotechnology is discussed. Based on the work of Kazakh scientists, the place and significance of the tunneling effect in modern physics are determined. The research results provide a deeper understanding of quantum phenomena and promote the development of their practical applications.

Dragica Vasileska, Gerhard Klimeck

Massimiliano Sassoli de Bianchi

The phenomenon of quantum tunneling challenges classical intuitions about particle behavior and offers profound insights into the nature of quantum entities. This article examines tunneling through the lens of an effect predicted by Thomas E. Hartman in 1962: the tunneling time-delay becomes independent of the barrier width as the latter increases, implying superluminal effective velocities that appear to conflict with relativistic constraints. Exploiting the inherent symmetries of transmitted and reflected time-delays, our analysis shows that a tunneling particle, like its reflected counterpart, completely avoids the barrier region. However, since it can be detected on the transmitted side of the barrier, the only logical conclusion is that the classical notion of spatiality is violated during the tunneling process. In other words, quantum tunneling and the associated Hartman effect strongly support the idea that quantum non-locality should be interpreted as quantum non-spatiality. The latter, according to the conceptuality interpretation of quantum mechanics, expresses the conceptual-like nature of quantum entities, which during measurement transition from an abstract state to a maximally concrete one, in full compatibility with the Hartman effect.