Table 3 Jordan–Wigner transformation for the main operators appearing in the Hamiltonian and in our ADAPT-VQE operator pool.

From: Nuclear shell-model simulation in digital quantum computers

 

Fermion operators

Qubit operators

\(n_p\)

\(a_p^{\dag }a_p\)

\(\dfrac{1}{2} (1-Z_p)\)

\(h_{pqrs}\)

\(\begin{array}{l} a_p^{\dag }a_q^{\dag }a_r a_s \\ \quad + a_r^{\dag }a_s^{\dag }a_p a_q\end{array}\)

\(\begin{array}{l} \dfrac{1}{8} P_{rs}^{pq}\, ( -X_p X_q X_r X_s + X_p X_q Y_r Y_s \\ \quad \qquad - X_p Y_q X_r Y_s- X_p Y_q Y_r X_s \\ \quad \qquad - Y_p Y_q Y_r Y_s + Y_p Y_q X_r X_s \\ \quad \qquad - Y_p X_q Y_r X_s - Y_p X_q X_r Y_s)\end{array}\)

\(T_{rs}^{pq}\)

\(\begin{array}{l} i(a_p^{\dag }a_q^{\dag }a_r a_s \\ \quad - a_r^{\dag }a_s^{\dag }a_p a_q)\end{array}\)

\(\begin{array}{l} \dfrac{1}{8} P_{rs}^{pq}\, ( -X_p Y_q Y_r Y_s - Y_p X_q Y_r Y_s \\ \quad \qquad + Y_p Y_q X_r Y_s + Y_p Y_q Y_r X_s \\ \quad \qquad +Y_p X_q X_r X_s + X_p Y_q X_r X_s \\ \quad \qquad - X_p X_q Y_r X_s - X_p X_q X_r Y_s)\end{array}\)

\(h_{pq}\)

\(a_p^{\dag }a_q + a_q^{\dag }a_p\)

\(\dfrac{1}{2}\left( \prod _{n=p+1}^{q-1}Z_n\right) \left( X_p X_q+Y_q Y_p\right)\)

\(T_{pq}\)

\(i(a_p^{\dag }a_q - a_q^{\dag } a_p)\)

\(\dfrac{1}{2}\left( \prod _{n=p+1}^{q-1}Z_n\right) \left( Y_p X_q-X_q Y_p\right)\)

  1. Indices run over \(p<q\) and \(r<s\), assuming that all are different. If two indices are repeated, then \(h_{pqpr}=-n_p h_{qr}\) and \(T_{pq}^{pr}=n_p T_{qr}\), with \(q<r\). We note that \(h_{pqpq}=-2n_p n_q\) and \(T_{pq}^{pq}=0\).