Quantum Field Theory – How Does Wave-Particle Duality Fit with QFT?

particle-physicsquantum mechanicsquantum-field-theorywave-particle-dualitywaves

It's heard quite often that fundamental particles (photons, quarks, etc) act as both particles and waves.

Now, I'm looking at it from a Quantum Field perspective. Is this localized energy ripple what the wave is? And is the fact that it is localized make it a particle?

Quantum Field

As shown in the GIF above, there is a red lattice, which is a quantum field. This is an oscillating ripple. Is this the wave nature of the particle? Is that what causes the result of Thomas Young's double slit experiment? Also, there is a green layer representing the particle's position, representing the disturbance in the quantum field as a particle. Is this the explanation for the photoelectric effect?

Ultimately, is this the explanation for the wave-particle duality?

Best Answer

No, this is not at all how quantum field theory works.

  1. A "quantum field" does not have a definite value at any time, it is an operator in the quantum theory, not something that has a fixed numerical value, therefore representing it as a lattice as you have done does not reflect the quantum nature of the field. This is the classical picture of the field, just like a point particle is the classical picture of the electron, not its quantum picture.

  2. The quantum field and the particle states are different things - the field is an operator and the particle is a state in the quantum theory. You can use (parts of) the quantum field operator to create particles, but the notion of particle is much more elusive than it being a simple ripple in a classical field. For more on this see this answer of mine on real particles and this question and its answers on virtual particles.

  3. The "wave-particle duality" is, in any case, a somewhat vague notion that has no real formal counterpart in modern quantum mechanics. Quantum objects are just that, quantum objects. They have aspects of waves (e.g. they can "interfere", they can obey wave-like equations, they "spread") and they have aspects of particles (e.g. they can (but not must be) localized at "points", they have mass) but they are neither. And I'm sure you can find quantum behaviour that you'll not be able to attribute to either a wavy or a particle nature, such as Bell experiments about entanglement (which cannot be explained classically, and hence any attempt to explain them with a particle or wave picture must necessarily fail).