The phenomenon you're referring to is known as the double-slit experiment with particles, which demonstrates the wave-particle duality of matter. In this experiment, it is possible to observe interference patterns similar to those seen with light waves.
To allow a single particle, such as an electron or a photon, to pass through both slits without destroying its wave nature, a setup known as a quantum eraser or delayed-choice experiment can be employed. Here's a simplified explanation of the experiment:
Particle Source: The experiment starts with a source that emits individual particles, such as electrons, one at a time.
Slit Arrangement: The particles encounter a barrier with two closely spaced slits. These slits act as wave sources, allowing the particle to exhibit wave-like behavior.
Detection Screen: Behind the double-slit barrier, there is a screen that detects the particles. Initially, if we observe the particles on the screen, they appear to have passed through one of the slits randomly and behave as particles, creating two separate clumps on the screen.
Adding Interference: Now, if a detector is placed near each slit to determine which path the particle took, the interference pattern disappears. The act of detecting the particle's path collapses the wave function, and the particle behaves like a classical particle, resulting in two distinct clumps on the screen.
Quantum Eraser: However, if the detectors near the slits are removed after the particles have passed through them, and additional detectors are placed to record which path the particles took later, the interference pattern reemerges. Even though the particles were not directly observed, the information about their paths was recorded later. This delayed-choice information erases the ability to determine which path the particles took, allowing the interference pattern to be observed again.
By manipulating the setup and the timing of measurements, it becomes possible to make it appear as though a single particle passed through both slits simultaneously while exhibiting wave-like interference behavior on the detection screen. This experiment demonstrates the fundamental concept of wave-particle duality in quantum mechanics.