Technical University of Munich
报告摘要：
Two-dimensional semiconductors have intriguing optical properties that make them particularly interesting for quantum photonics, sensing, metrology, and simulation. They host strongly bound excitons having linewidths close to the Fourier limit, they have strong spin-orbit coupling that provides direct optical access to spin and valley degrees of freedom, they can be readily hetero-integrated onto a wide variety of different photonic platforms to manipulate light-matter coupling.
In this talk, I begin by describing how optically active defects can be site-selectively generated in monolayer MoS2 using a focused helium ion beam [1,2]. Similarly, N-ions can also be used to generate the negatively charged Boron vacancy (VB-), a defect that is paramagnetic with spin-coherence times approaching ~100ns at room temperature [4-6]. We will explore how pristine 2D heterostructures can be integrated into Si3N4 nanobeam cavities that simultaneously host high ？？ >105 photonic cavity modes as well as local nano-mechanical vibronic modes. Using such cavities, we explore the lasing of moiré trapped dipolar interlayer excitons [7], nonlocal collective light-matter interactions [5-7] and multimodal vibronic–phonon–photon couplings mediated by electronic excitations [8]. Finally, I will present recent experiments in which we observe signatures of strongly correlated states in moiré lattices formed by WSe2-WS2 bilayers with electrical control of doping [9]. We observe correlated insulating states at fractional fillings of the moiré lattice and identify the observed features as arising from charge-ordered states at commensurate filling fractions that range from generalized Wigner crystals to charge density waves. Such systems set the scene for using moiré superlattices to quantum many-body problems that are described by the two-dimensional extended Hubbard models or spin models with long-range charge–charge and exchange interactions.
[1] J. Klein et al. Nature Comm 10, 2755 (2019), [2] A. H？tger et al. npg 2D materials and applications 7, 30, (2023), [3] C. Qian et al. Nano Lett, 22, 13, 5137–5142, (2022), [4] R. Rizzato et al. Nature Comm. 14, 5089, (2023), [5] C. Qian et al. Phys. Rev. Lett. 128, 237403 (2022), [6] A. Gottscholl et al., Sci. Adv. 7, eabf3630, (2021), [7] C. Qian et al. Phys. Rev. Lett. 130, 126901, (2023), [8] C. Qian et al. arXiv 2210.00150 (2023), [9] Y. Xu et al. Nature, 587, (2020)
报告人简介：
Jonathan Finley studied at the Universities of Manchester and Sheffield in the U.K., completing his Ph.D. in 1997 under the guidance of M. S. Skolnick (FRS) working on the spectroscopy of III-V nanostructures. Subsequently, in 1998 he moved to the Technical University of Munich (TUM) with a fellowship of The Royal Society. At this time, he started to work on the physics of quantum dots and other semiconductor nanostructures. After a brief hiatus at the University of Sheffield (1999-2002), he returned to Munich in 2002 where he was Junior Group leader at the Max Planck Institut for Quantum Optics (2002), before being appointed as a tenured associate (C3) professorship in 2003. Since 2013 he has been a Full Professor at TUM (W3), where he leads the chair for Semiconductor Nanomaterials and Quantum Systems.
邀请人：钱琛江