Ab-initio theory of orbitally coupled spin Hamiltonians for Jahn-Teller active quantum defects embedded in solids
ORAL
Abstract
Over the past decades, a variety of crystallographic point defects were identified in 2D and 3D host materials such as diamond, silicon, SiC, or BN. Initially, the characterization of defects was driven by materials science point of view to unravel and understand their physics across different hosts. More recently, new proposed applications have been emerged for example: quantum applications. At the same time, ab-initio calculations become a versatile tool to unravel the properties of defects. However, determining the key interactions, especially spin Hamiltonians for orbitally degenerate multiplets within ab initio density functional theory (DFT) remains non-trivial task[1-4].
We show by means of DFT calculations that all SDS (zero-field), SAI (hyperfine) and IPI (quadrupolar) 3×3 tensors acting in |3E〉optical excited upper triplet state of NV are entangled with the 2× orbital degeneracy (“mL=±1”) that of σ−|e+〉=|e−〉electronic orbitals localized on the defect. Therein, we show that an additional “ΔmI = ±2” relaxation channel opens up for 14N nuclear spin during “green laser (532-nm)” illumination. Consistent with experimental [1] and theoretical [2] results, this phenomenon is due to nontrivial “P2(σ+I−2+σ−I+2)” terms arising from orbital degrees of freedom mediated by the Jahn-Teller effect. Moreover, we show that orbitally coupled terms (S−I−σ++h.c.) can arise in the hyperfine spectroscopy that of G4V: SiV(−) , GeV(−) , SnV(−) , PbV(−) defects in diamond [3]. The methodology is general and we note that these phenomena is strongly mediated by electron-phonon coupling though Jahn-Teller Ham reduction factors that all can be determined by means of our jahn-teller-dynamics [7,8] python package.
In my present talk, I will depict a general ab-initio theory that can be used to determine spin Hamiltonians for orbitally degenerate levels.
[1] R. Monge, T. Delord, G. Thiering, A. Gali, and C. A. Meriles, Phys. Rev. Lett. 131, 236901 (2023).
[2] G. Thiering, A. Gali, Phys. Rev. Applied 24, 044027 (2025).
[3] M. Mohseni, L. Razinkovas, V. Zalandauskas, G. Thiering, A. Gali, Phys. Rev. B 112, 155201 (2025).
[4] G. Thiering, A. Gali, J. Appl. Phys. 136, 084401 (2024).
[5] B. Tóth, A. Gali, G. Thiering https://pypi.org/project/jahn-teller-dynamics/
[6] G. Thiering, A. Gali, https://hdl.handle.net/21.15109/ARP/O4CEI6
We show by means of DFT calculations that all SDS (zero-field), SAI (hyperfine) and IPI (quadrupolar) 3×3 tensors acting in |3E〉optical excited upper triplet state of NV are entangled with the 2× orbital degeneracy (“mL=±1”) that of σ−|e+〉=|e−〉electronic orbitals localized on the defect. Therein, we show that an additional “ΔmI = ±2” relaxation channel opens up for 14N nuclear spin during “green laser (532-nm)” illumination. Consistent with experimental [1] and theoretical [2] results, this phenomenon is due to nontrivial “P2(σ+I−2+σ−I+2)” terms arising from orbital degrees of freedom mediated by the Jahn-Teller effect. Moreover, we show that orbitally coupled terms (S−I−σ++h.c.) can arise in the hyperfine spectroscopy that of G4V: SiV(−) , GeV(−) , SnV(−) , PbV(−) defects in diamond [3]. The methodology is general and we note that these phenomena is strongly mediated by electron-phonon coupling though Jahn-Teller Ham reduction factors that all can be determined by means of our jahn-teller-dynamics [7,8] python package.
In my present talk, I will depict a general ab-initio theory that can be used to determine spin Hamiltonians for orbitally degenerate levels.
[1] R. Monge, T. Delord, G. Thiering, A. Gali, and C. A. Meriles, Phys. Rev. Lett. 131, 236901 (2023).
[2] G. Thiering, A. Gali, Phys. Rev. Applied 24, 044027 (2025).
[3] M. Mohseni, L. Razinkovas, V. Zalandauskas, G. Thiering, A. Gali, Phys. Rev. B 112, 155201 (2025).
[4] G. Thiering, A. Gali, J. Appl. Phys. 136, 084401 (2024).
[5] B. Tóth, A. Gali, G. Thiering https://pypi.org/project/jahn-teller-dynamics/
[6] G. Thiering, A. Gali, https://hdl.handle.net/21.15109/ARP/O4CEI6
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Publication: Originally started with this [1] work:
[1] R. Monge, T. Delord, G. Thiering, A. Gali, and C. A. Meriles, Phys. Rev. Lett. 131, 236901 (2023).
then extended into the following:
[2] G. Thiering, A. Gali, Phys. Rev. Applied 24, 044027 (2025).
[3] M. Mohseni, L. Razinkovas, V. Zalandauskas, G. Thiering, A. Gali, Phys. Rev. B 112, 155201 (2025).
Presenters
-
Gergo Thiering
- HUN-REN Wigner Research Centre for Physics