Residual electronic correlation and QED effects in fine-structure splitting of ground configuration for the boron isoelectronic sequence

Bayesian phase difference estimation algorithm for direct calculation of fine structure splitting: accelerated simulation of relativistic and quantum many-body effects

“…In the above equations, c is the speed of light, α and β are the 4 × 4 Dirac matrices, p i is the momentum operator associated with the i th electron, V n (r i ) is the electron-nucleus potential, and 1/r ij is the electron-electron Coulomb interaction term (in a.u.). A recent theoretical study by Wan and coworkers showed that relative contributions of Breit interactions to the fine structure splitting of B-isoelectronic sequence are significant for light elements, and is as large as 14.55% for neutral boron [28].…”

“…In this backdrop, we report numerical quantum simulations for the direct calculation of fine structure splitting of boron (B) isoelectronic sequence (5 ⩽ Z ⩽ 103, where Z is the atomic number of the considered system) by using a Bayesian phase difference estimation (BPDE) algorithm in conjunction with the four-component relativistic Dirac-Coulomb and Dirac-Coulomb-Breit Hamiltonians. Fine structure splitting is, as discussed below in detail, a purely relativistic effect and is affected by electron correlation, and therefore sophisticated treatments of both relativistic and correlation effects are necessary to calculate it quantitatively [22][23][24][25][26][27][28]. Since experimental fine structure splittings of wide variety of isoelectronic ions have been reported [29], they are good testing grounds for the sophisticated quantum chemical calculations on a quantum computer.…”