- #1

HighPhy

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There are plenty of threads on PF dealing with the issue of "wave-particle duality".

Although not unanimously, many agree that the concept of "wave-particle duality" is outdated. Electrons, photons and all of the underlying entities are neither waves nor particles, but quantum fields, and we can do certain wave-like experiments that let quantum fields behave like particles, and other particle-like experiments that let them behave like waves.

I have doubts not only about the term "duality," but also about "wave-particle duality" in the double-slit experiment. I'll try to put my doubt within a context.

From the very beginning, I was taught in school that:

Bohr conceived the atom with electron making circular orbits around the nucleus with its levels (by following Planck's quantization of energy). Later Schroedinger, thanks to Young's

**double-slit experiment demonstrating "wave-particle duality"**, abandoned the concept of an orbit to introduce that of an orbital and to see how the electron does not perform a well-defined orbit, but rather is chaotic.

The electron can be in an area described by the wave function, and the square modulus of the wave function (always greater than or equal to zero) returns the probability that the electron is at a given point, which, however, cannot be known because of Heisenberg's Undeterminacy Principle.

So the real model of an atom is not the one with a ball of mass formed by protons and neutrons and precise orbits of electrons surrounding it, but the one that predicts an electron cloud in which there is a greater probability of finding an electron.

Having finished with the context, of which I am not sure, I express my confusion.

It is said that the double-slit experiment demonstrates "wave-particle duality".

In this Insight article it is said that:

Quantum mechanics is known for its strangeness, including phenomena like wave-particle duality, which allows particles to behave like waves. The double-slit experiment is a key demonstration of this duality, showing that even single particles, like photons, exhibit wave-like behavior. When the experiment measures which slit a particle goes through, it behaves like a particle. When this measurement is not made, it exhibits interference patterns typical of waves.

The transformation from wave-like behavior to particle-like behavior is intimately related to Heisenberg’s uncertainty principle

[...] using detectors to measure each photon’s slit identity (i.e. which slit the photon passed through) prevents any wave-like behavior, just as if each photon had traveled in complete isolation as a single particle. If both slots are left open (and no photodetectors are used) then the original interference pattern is restored, as if the individual photons behave like waves [...]. This is the famous wave-particle duality.

So my question is:

Is the fact that the double-slit experiment demonstrates wave-particle duality a misconception?

Or does the double-slit experiment (1801) really prove "wave-particle duality" but must be overcome due to the fact that the latter is an outdated concept?

Or are there particular explanations that allow this experiment to be placed in the perspective of "modern quantum theory" despite the fact that it could demonstrate "wave-particle duality"?