EntanglementBanner-3b.png

First-principles theory of spin defects in 2D crystals for quantum applications

From Qubits
(Redirected from Seo, Hosung)
  • Speaker: Seo, Hosung (Ajou Univ., Korea)


Deep-level spin defects in wide-gap semiconductors are promising platforms for applications in quantum information processing, quantum sensing, and quantum photonics [1]. In particular, several point defects in two-dimensional materials such as h-BN have recently emerged as room-temperature single photon emitters (SPEs) with excellent optical stability and brightness [2] and potentially spin qubits [3]. In this study, we use first-principles theory to investigate the optical and spin properties of deep-level defects in two-dimensional crystals including h-BN and MoS2. First, we discuss our recent combined experimental and theoretical study of Stark tuning of SPE’s in h-BN [4,5]. We show that it is possible to control the SPEs’ optical energy by applying an out-of-plane electric field and we suggested that the presence of the out-of-plane dipole of the SPEs may be originated from spontaneous symmetry breaking of the SPEs’ defect structure [4]. We consider diverse defect candidates for SPEs in h-BN such as VNCB, VNNB and we discuss the potential mechanism of the symmetry lowering process of the defect models and its physical implications for their application as single photon emitters [5]. In the second part of the talk, we describe spin decoherence in two-dimensional materials, using spin Hamiltonian and a cluster expansion method [6]. We show that isotopic purification could be much more effective in 2D than in 3D materials. We also discuss additional factors influencing the optimization of spin qubit hosts.


[1] W. F. Koehl, H. Seo, G. Galli, and D. A. Awschalom, MRS Bulletin 40, 1146-1153 (2015).

[2] M. Toth and I. Aharonovich, Annu. Rev. Phys. Chem. 70, 123 (2019).

[3] A. L. Exarhos, D. A. Hopper, R. N. Patel, M. W. Doherty, and L. C. Bassett, Nat. Comm. 10, 222 (2019).

[4] G. Noh, D. Choi, J. Kim, D. Im, Y. Kim, H. Seo, and J. Lee, Nano Lett. 18, 4710 (2018).

[5] J. Bhang, D. Yim, and H. Seo, in preparation (2019).

[6] M. Ye, H. Seo, and G. Galli, npj Comp. Mater., in press (2019).

Retrieved from "https://qubits.korea.ac.kr/Qubits/index.php?title=First-principles_theory_of_spin_defects_in_2D_crystals_for_quantum_applications&oldid=517"