Physics, Condensed Matter Physics, Quantum Computing.
that the operator acts upon and say that a^{†}_{iσ} creates a fermion at site i with spin σ, while a_{iσ} destroys a fermion at site i with spin σ. Similarly, we call b^dag a bosonic creation operator (letter doesn’t matter) and b a bosonic annihilation operator. With a specified index, we say that