Yes, it is indeed possible to pass a single electron or a single photon through the double-slit experiment. In fact, this is precisely how the experiment is often conducted to observe the wave-particle duality phenomenon on an individual particle level.
When it comes to detecting a single electron or a single photon, specialized detectors are used. For electrons, a common detector is a device called a "channel electron multiplier" or "CEM." It can detect individual electrons by amplifying the resulting electron signal into a measurable current or voltage. Similarly, for photons, detectors such as photomultiplier tubes or avalanche photodiodes are commonly used, which are capable of sensing individual photons.
These detectors are designed with high sensitivity and are able to register the passage of individual particles. They work based on principles such as the emission of secondary electrons or the generation of a measurable electrical signal when a particle interacts with a material in the detector.
However, it's important to note that the act of detection itself can influence the behavior of the particle. In the double-slit experiment, when the detectors are introduced to observe the particles, the wave-like interference pattern disappears, and the particles behave more like particles rather than waves. This is known as the "observer effect" in quantum mechanics, where the act of measurement disturbs the system being observed.
While there are detectors that can sense the passage of individual electrons or photons, their implementation and precise measurements often require sophisticated equipment and controlled environments. Conducting such experiments at home may be challenging due to the technical requirements and the need for precise calibration. However, there are simplified versions of the double-slit experiment using light that can be carried out on a smaller scale in educational settings or home setups.