Stern Gerlach experiment
Channel: Nirvana study
Date: 2024-01-24

The Stern-Gerlach experiment is a quantum mechanics experiment that demonstrates the quantization of angular momentum and the concept of spin. Here's a more detailed explanation:

1. **Setup:**
   - Particles, typically silver atoms or other particles with magnetic moments, are prepared in an oven and directed towards a region with an inhomogeneous magnetic field.

2. **Magnetic Field:**
   - The magnetic field is arranged so that it varies along a specific direction, often chosen as the z-axis.

3. **Quantization of Angular Momentum:**
   - In classical physics, you might expect particles with magnetic moments to align with the magnetic field in a continuous manner. However, quantum mechanics introduces the idea of quantized angular momentum.

4. **Quantum Spin:**
   - The particles, such as electrons, have an intrinsic quantum property called spin. Spin is a form of angular momentum that has quantized values, usually expressed as ±ħ/2 (where ħ is the reduced Planck constant).

5. **Experimental Result:**
   - Surprisingly, when the particles pass through the Stern-Gerlach apparatus, they don't spread out uniformly according to classical expectations. Instead, they get separated into distinct spots on a detector screen. This is due to the quantized values of the angular momentum component along the chosen direction.

6. **Two-Spot Result:**
   - In the simplest case, particles are observed to land in only two distinct spots on the detector screen. This result demonstrates that the angular momentum component along the chosen direction is quantized and can only take one of two possible values.

7. **Quantum Superposition:**
   - Before measurement, the quantum state of the particle is often described as a superposition of both possible spin states. However, upon measurement, the system 'chooses' one of the quantized values, leading to the observed two-spot pattern.

The Stern-Gerlach experiment is foundational in quantum mechanics, illustrating the inherently probabilistic nature of measurements and the discrete nature of certain physical properties, such as spin.

## by Ashwani Thakur