For the ground state of the homogeneous electron gas (jellium), it is shown how the cumulant decomposition of the 2-matrix leads to the cumulant decomposition of the structure factors Sa,p(q) for the antiparallel (a) ...For the ground state of the homogeneous electron gas (jellium), it is shown how the cumulant decomposition of the 2-matrix leads to the cumulant decomposition of the structure factors Sa,p(q) for the antiparallel (a) and parallel (p) spin pairs and how it simultaneously allows one to derive the momentum distribution n(k), which is a one-body quantity [Phys. Rev. A 86, 012508 (2012)]. The small-q and large-q behavior of Sa,p(q), and their normalizations are derived and compared with the results of P. Gori-Giorgi et al. [Physica A 280, 199 (2000) and Phys. Rev. B 61, 7353 (2000)].展开更多
In this presentation we present the Green’s functions and density of states for the most frequently encountered 2D lattices: square, triangular, honeycomb, kagome, and Lieb lattice. Though the results are well known,...In this presentation we present the Green’s functions and density of states for the most frequently encountered 2D lattices: square, triangular, honeycomb, kagome, and Lieb lattice. Though the results are well known, we hope that its derivation performed in a uniform way provides some pedagogical value.展开更多
Divacancy spins implement qubits with outstanding characteristics and capabilities in an industrial semiconductor host On the other hand,there are still numerous open questions about the physics of these important def...Divacancy spins implement qubits with outstanding characteristics and capabilities in an industrial semiconductor host On the other hand,there are still numerous open questions about the physics of these important defects,for instance,spin relaxation has not been thoroughly studied yet.Here,we carry out a theoretical study on environmental spin-induced spin relaxation processes of divacancy qubits in the 4H polytype of silicon carbide(4H-SiC).We reveal all the relevant magnetic field values where the longitudinal spin relaxation time T,drops resonantly due to the coupling to either nuclear spins or electron spins.We quantitatively analyze the dependence of the T,time on the concentration of point defect spins and the applied magnetic field and provide ananalytical expression.We demonstrate that dipolar spin relaxation plays a significant role both in as-grown and ion-implanted samples and it often limits the coherence time of divacancy qubits in 4H-SiC.展开更多
文摘For the ground state of the homogeneous electron gas (jellium), it is shown how the cumulant decomposition of the 2-matrix leads to the cumulant decomposition of the structure factors Sa,p(q) for the antiparallel (a) and parallel (p) spin pairs and how it simultaneously allows one to derive the momentum distribution n(k), which is a one-body quantity [Phys. Rev. A 86, 012508 (2012)]. The small-q and large-q behavior of Sa,p(q), and their normalizations are derived and compared with the results of P. Gori-Giorgi et al. [Physica A 280, 199 (2000) and Phys. Rev. B 61, 7353 (2000)].
文摘In this presentation we present the Green’s functions and density of states for the most frequently encountered 2D lattices: square, triangular, honeycomb, kagome, and Lieb lattice. Though the results are well known, we hope that its derivation performed in a uniform way provides some pedagogical value.
基金We acknowledge support from the Knut and Alice Wallenberg Foundation through the WBSQD2 project(Grant No.2018.0071)Support from the Swedish Government Strategic Research Area SeRC and the Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linköping University(Faculty Grant SFO-Mat-LiU No.200900971)is gratefully adknowledged.V.l.adknowledges the support from the MTA Premium Postdoctoral Research Program,the Hungarian NKFIH grantsNo.KKP129866 of the National Excellence Program of Quantum-coherent materials project+3 种基金the NKFIH through the National Quantum Technology Program(Grant No.2017-1.2.1-NKP-2017-00001)the Quantum Information National Laboratory sponsored by the Ministry of Innovation and Technology of Hungary.N.T.S.adknowl-edges the support from the Swedish Research Coundl(Grant Na.VR 2016-04068)the EU H2020 project QuanTELCO(Grant No.862721)The calculations were performed on resources provided by the Swedish National Infrastructure for Computing(SNIC)at the National Supercomputer Centre(NSC)partially funded by the Swedish Research Council through grant agreement No.2018-05973.
文摘Divacancy spins implement qubits with outstanding characteristics and capabilities in an industrial semiconductor host On the other hand,there are still numerous open questions about the physics of these important defects,for instance,spin relaxation has not been thoroughly studied yet.Here,we carry out a theoretical study on environmental spin-induced spin relaxation processes of divacancy qubits in the 4H polytype of silicon carbide(4H-SiC).We reveal all the relevant magnetic field values where the longitudinal spin relaxation time T,drops resonantly due to the coupling to either nuclear spins or electron spins.We quantitatively analyze the dependence of the T,time on the concentration of point defect spins and the applied magnetic field and provide ananalytical expression.We demonstrate that dipolar spin relaxation plays a significant role both in as-grown and ion-implanted samples and it often limits the coherence time of divacancy qubits in 4H-SiC.
