Quantum tunneling time

  title={Quantum tunneling time},
  author={Paul C. W. Davies},
  journal={American Journal of Physics},
  • P. Davies
  • Published 1 March 2004
  • Physics
  • American Journal of Physics
A simple model of a quantum clock is applied to the old and controversial problem of how long a particle takes to tunnel through a quantum barrier. The model has the advantage of yielding sensible results for energy eigenstates and does not require the use of time-dependent wave packets. Although the treatment does not forbid superluminal tunneling velocities, there is no implication of faster-than-light signaling because only the transit duration is measurable, not the absolute time of transit… 

Anatomy of Quantum Tunneling

We use complex classical solutions to provide a simple and transparent treatment of quantum tunneling. We show that the imaginary part of the tunneling coordinate may be weakly measured, and that it

On the status of quantum tunnelling time

  • G. Field
  • Physics
    European Journal for Philosophy of Science
  • 2022
How long does a quantum particle take to traverse a classically forbidden energy barrier? In other words, what is the correct expression for quantum tunnelling time? This seemingly simple question

Quantum Tunneling Time: Relativistic Extensions

Several years ago, in quantum mechanics, Davies proposed a method to calculate particle’s traveling time with the phase difference of wave function. The method is convenient for calculating the

Aharonov-Bohm effect in the tunnelling of a quantum rotor in a linear Paul trap.

It is demonstrated that the charged particles in this quantum Tunnelling system are coupled to the vector potential of a magnetic field throughout the entire process, even during quantum tunnelling, as indicated by the manifestation of the Aharonov-Bohm effect in this system.

Existence and nonexistence of an intrinsic tunneling time

Using a time operator, we define a tunneling time for a particle going through a barrier. This tunneling time is the average of the phase time introduced by other authors. In addition to the delay

Simulations in quantum tunneling

We study the timing effects of nonrelativistic wave packet tunneling through a barrier using a numerical simulation readily accessible to an undergraduate audience. We demonstrate that the peak of

Scattering a quantum particle on the potential step: Characteristic times for transmission and reflection

We present a new model of scattering a quantum particle on the potential step, which reconstructs the prehistory of the subensembles of transmitted and reflected particles by their final states.

Barrier interaction time and the Salecker-Wigner quantum clock: Wave-packet approach

The time-of-flight measurement approach of Peres based on the Salecker-Wigner quantum clock is applied to the one-dimensional scattering of a wave packet from a rectangular barrier. By directly



Measurement of the single-photon tunneling time.

Using a two-photon interferometer, the time delay for a photon to tunnel across a barrier consisting of a 1.1-μm-thick 1D photonic band-gap material is measured, consistent with the group delay («phase time»), but not with the semiclassical time.

Properties of a quantum system during the time interval between two measurements.

  • AharonovVaidman
  • Physics
    Physical review. A, Atomic, molecular, and optical physics
  • 1990
A description of quantum systems at the time interval between two successive measurements is presented, and how this approach leads to a new concept: a weak value of an observable.

How the result of a measurement of a component of the spin of a spin-1/2 particle can turn out to be 100.

We have found that the usual measuring procedure for preselected and postselected ensembles of quantum systems gives unusual results. Under some natural conditions of weakness of the measurement, its

Measurement of time by quantum clocks

A clock is a dynamical system which passes through a succession of states at constant time intervals. If coupled to another system, it can measure the duration of a physical process and even keep a

Barrier interaction time in tunneling

Over sixty years ago, it was suggested that there is a time associated with the passage of a particle under a tunneling barrier. The existence of such a time is now well accepted; in fact the time

Time as an observable

The role of time in quantum mechanics is discussed. The differences between ordinary observables and an observable which corresponds to the time of an event is examined. In particular, the

Quantum mechanics and the equivalence principle

A quantum particle moving in a gravitational field may penetrate the classically forbidden region of the gravitational potential. This raises the question of whether the time of flight of a quantum

Quantum Limitations of the Measurement of Space-Time Distances

This article deals with the limitations which the quantized nature of microscopic systems imposes on the possibility of measuring distances between space-time events. It is proposed to use only

Larmor precession and the traversal time for tunneling

Baz' and Rybachenko have proposed the use of the Larmor precession as a clock to measure the time it takes a particle to traverse a barrier. An applied magnetic field is confined to the barrier. The

Superluminal tunneling through two successive barriers(

We study the phenomenon of one-dimensional non-resonant tunneling through two successive (opaque) potential barriers, separated by an intermediate free region R ,b y analyzing the relevant solutions