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arXiv · 1703.04175

Two-electron states of a group V donor in silicon from atomistic full configuration interaction

Archana Tankasala·Joseph Salfi·Juanita Bocquel·Benoit Voisin·Muhammad Usman·Gerhard Klimeck·Michelle Y. Simmons·Lloyd C. L. Hollenberg·Sven Rogge·Rajib Rahman
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Abstract

Two-electron states bound to donors in silicon are important for both two qubit gates and spin readout. We present a full configuration interaction technique in the atomistic tight-binding basis to capture multi-electron exchange and correlation effects taking into account the full bandstructure of silicon and the atomic scale granularity of a nanoscale device. Excited $s$-like states of $A_1$-symmetry are found to strongly influence the charging energy of a negative donor centre. We apply the technique on sub-surface dopants subjected to gate electric fields, and show that bound triplet states appear in the spectrum as a result of decreased charging energy. The exchange energy, obtained for the two-electron states in various confinement regimes, may enable engineering electrical control of spins in donor-dot hybrid qubits.

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Archana Tankasala, Joseph Salfi, Juanita Bocquel, Benoit Voisin, Muhammad Usman, Gerhard Klimeck, Michelle Y. Simmons, Lloyd C. L. Hollenberg, Sven Rogge, Rajib Rahman. 2017-03-12. Two-electron states of a group V donor in silicon from atomistic full configuration interaction. https://doi.org/10.1103/physrevb.97.195301

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