= Sublattice pseudospin in graphene
{title2=$\langle\boldsymbol\sigma\rangle=(\cos\phi,\sin\phi,0)$}
At $\mathbf K_+$ and positive <energy>, a normalized <eigenvector> for $\mathbf q=|\mathbf q|(\cos\phi,\sin\phi)$ is $(1,e^{i\phi})/\sqrt2$. Its <Pauli matrix> expectation values give the displayed direction. This <pseudospin> records the relative amplitudes and phase on the two sublattices. Real <spin> supplies another label; confusing these two labels would double-count states and misinterpret the two-band <Hamiltonian>.
Back to article page
