When a single photon is sent through a double-slit experiment, it exhibits a wave-particle duality characteristic. The behavior of the photon is probabilistic, meaning that we cannot determine with certainty which slit the photon goes through.
In the double-slit experiment, when photons are sent through two slits, they form an interference pattern on the screen behind the slits. This pattern arises due to the wave-like nature of photons interfering with themselves. Importantly, even when photons are sent through one at a time, and thus cannot interact with each other, the interference pattern still emerges gradually over time as more and more photons are detected.
The intriguing aspect is that when a single photon is detected on the screen, it does not reveal which specific path or slit it took. The photon behaves as if it went through both slits simultaneously and interfered with itself, resulting in an interference pattern. The probability distribution of where the photon is likely to be detected on the screen corresponds to the interference pattern, indicating the wave-like nature of the photon.
Therefore, in the case of a single photon, it is not possible to determine with certainty which slit the photon went through, as it exhibits wave-like behavior by passing through both slits simultaneously and interfering with itself.