 Topological quantum number

Topological quantum numbers are integer values that arise in the context of topological phases of matter and quantum field theories, particularly in condensed matter physics. They characterize different phases of a system based on their global properties rather than local properties, which can be crucial for understanding phenomena that are stable against local perturbations. A few key points about topological quantum numbers are: 1. **Robustness**: Topological quantum numbers are robust against small perturbations or changes in the system.