Print the total binary entropy

TBE (bit labels);

shows the sum of the binary entropies of individual qubits specified by bit labels. A binary entropy of the $i$-th qubit is

$$H_b(\varepsilon_i)=-\left(\frac{1+\varepsilon_i}{2}\log_2\frac{1+\varepsilon_i}{2}+\frac{1-\varepsilon_i}{2}\log_2\frac{1-\varepsilon_i}{2}\right),$$ (18)

where $\varepsilon_i$ is the intrinsic polarization of the $i$-th qubit, which is calculated according to the eigenvalues, $\lambda_i$ and $1-\lambda_i$, of the reduced density operator $\tilde\rho_i$ of the qubit. In other words, the command shows the total binary entropy

$$S_b=\sum_{specified~~i}S_{vN}(\tilde\rho_i),$$ (19)

where $S_{vN}$ denotes the von Neumann entropy.