What Does h.c. Signify in Quantum Mechanics Formulas?

[phonon44145]

A textbook gives the following interaction Hamiltonian describing the interaction of an atom (having transition dipole moment \mu) with a photon whose polarization can be \epsilon_{1} or \epsilon_{2}):

H = g \Sigma^{2}_{s=1}\mu\bullet\epsilon_s\sigma^{-}a^{+}_{s} + h.c.

where \sigma^{-} is Pauli spin-flip operator and a^{+}_{s} is the creation/annihilation operator.

What does "h.c." stand for in this formula?

 

[Polyrhythmic]

Hermitean conjugate.

 

[phonon44145]

Thanks for the quick reply. But I still cannot quite see how to write the second term explicitly. Am I correct in assuming that μ and ϵ1, ϵ2 should not change, σ− will become σ+, and creation operator will change to annihilation operator?

 

[phonon44145]

Also, what does g stand for - gyromagnetic ratio?