非線性光場調控、分子量子比特框架、單分子增強控制 、β衰變半衰期 | 本周物理講座

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報告人：Tatsuya Miki，Saitama University

時間：10月14日（周二）10:00

單位：Asian-Pacific Condensed Matter Physics (CMP) seminars

鏈接：

摘要：

Chiral materials have attracted significant attention for their unique electronic phenomena, such as cross-correlation responses, chirality-induced spin selectivity (CISS), and circular dichroism. To understand and control the material chirality, it is important to consider the quantitative measure that can continuously characterize the chirality of electrons, going beyond the binary distinction of “left” and “right” . Recently, electron chirality, based on relativistic quantum theory, has been proposed as a quantitative measure of chirality. However, it is still unclear which physical parameters in solids control electron chirality and how this connects to the experimentally observable quantity.

In this talk, we will present the results of quantitative evaluations of the electron chirality using first-principles calculations. The electron chirality exhibits rapid sign changes with respect to the chemical potential, indicating the possibility of controlling right- and left-handed electrons through the small chemical potential shift, such as electron or hole doping. Furthermore, we will demonstrate that electron chirality can be observed experimentally by using circularly polarized light in photoelectron spectroscopy. Finally, to gain clearer insight into the origin of electron chirality, we also study simplified atomic models with chiral crystal fields and will present the results of this analysis.

報告人簡介：

Tatsuya Miki is a Specially Appointed Researcher at the Institute for Materials Research, Tohoku University. His research focuses on the theoretical and computational study of strongly correlated electron systems and emergent quantum phenomena in condensed matter physics.

He received his Ph.D. in Physics from Saitama University in 2025, where he also earned his M.Sc. in 2023 and B.Sc. in 2021. During his doctoral studies, he was awarded the prestigious JSPS Research Fellowship for Young Scientists (DC1), recognizing his outstanding potential as an early-career researcher. He joined the Institute for Materials Research at Tohoku University in 2025.

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報告人：Maja Colautti，National Institute of Optics，CNR-INO

時間：10月14日（周二）16:00

單位：清華大學物理系

地點：物理樓W105

摘要：

The generation and manipulation of quantum states of light is required for key applications, such as photonic quantum simulation, linear optical quantum computing, quantum communication protocols, and quantum metrology. In this context, I will present our recent advancements in using single organic molecules at cryogenic temperature as bright and stable sources of coherent single photons in the solid state. In particular, I will focus on our results on two-photon interference (TPI) experiments performed between distinct molecules on the same chip, and our recent insights on how to mitigate the practical limitations on the TPI among distinct emitters via the control of the electrical environment at the nanoscale. Indeed, we recently provided experimental demonstration of a hybrid tuning method for controlling the frequency of quantum emitters and at the same time to reduce the emitter sensitivity to charge noise, controlling spectral fluctuations . This successful strategy is based on the combined use of the electric field generated by electrodes and of optically excited long-lived charge states, which provide two efficient knobs for enhanced control of single-molecule emitters for quantum photonic experiment.

Dibenzoterrylene-doped nanocrystals of anthracene are dispersed on a glass substrate, nanostructured with 4 μm gap interdigitated gold electrodes. A combination of optical pumping and electrodegenerated electric field is implemented (electrically guided optical Stark shift: EGOSS), yielding a high degree of control on the local applied field with high spatial resolution and out-of-plane orientation. This allows for a reduction of spectral fluctuation (by a factor of 12) for a given frequency shift, with respect to the case of an in-plane-only electric field manipulation. In this way, the emission frequencies of single molecules can be tuned without degrading their spectral stability.

報告人簡介：

Maja Colautti did her PhD in atomic and molecular photonics at the European Laboratory for Non-Linear Spectroscopy (LENS) in Florence, from 2016 to 2020, during which she developed hybrid strategies to efficiently integrate organic quantum emitters on chip. In 2021 she was visiting PostDoc Researcher at the Technical University of Denmark and at the Niels Bohr Institute in Copenhagen. During this period, she also worked for the Sparrow Quantum start-up developing quantum dot based devices for quantum technologies applications. Currently, she is a fixed term researcher at the National Institute of Optics in Florence, focusing her research on organic quantum emitters and hybrid nanophotonic strategies for diverse quantum applications.

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報告人：李貴新，南方科技大學

時間：10月15日（周三）15:10

單位：北京大學物理學院

地點：物理學院中212教室

摘要：

非線性光學超構表面是一類由空間變化的功能基元組成的超薄非線性光學器件。通過合理選擇超構功能基元的材料組成、空間對稱性，人們可以在亞波長尺度上對超構表面上產生的諧波進行多維度光場調控。通過構建具有旋轉對稱性的等離激元超構單元，可連續改變人工結構材料中非線性極化率的幾何相位，進而對超構表面上產生的諧波、太赫茲波的振幅、偏振、波前進行調控。此外，將光學幾何相位的概念推廣到傳統非線性光學晶體研究中，為控制諧波產生過程中的光自旋-軌道相互作用研究提供了新的視角。

報告人簡介：

李貴新，南方科技大學工學院材料科學與工程系、精密光學工程中心教授，2023年度美國光學學會會士、求是科技基金會2019年杰出青年學者獎獲得者。主要研究領域：光學超構表面、非線性光場調控、幾何相位，研究工作曾多次被《自然-光子學》、《自然-納米技術》、《自然-物理》作為亮點報道。擔任OpticsExpress副編輯。

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報告人：Nobuo Hinohara，University of Tsukuba, Japan

時間：10月16日（周四）15:00

單位：中國科學院理論物理研究所

地點：南樓6520

摘要：

The quasiparticle random-phase approximation (QRPA) is a widely used framework for describing nuclear collective excitations, such as giant resonances and low-energy modes, within the mean-field or density functional theory (DFT). However, the construction and diagonalization of the QRPA matrix in the two-quasiparticle basis can be computationally demanding, especially when nuclear deformation is taken into account.

To address this challenge, the finite-amplitude method (FAM) has been proposed as an efficient approach to solve the QRPA equations within the time-dependent DFT framework. In this talk, I will present an overview of the FAM, with an emphasis on its implementation in existing DFT codes. I will also discuss its extensions to various QRPA applications, including low-energy collective excitations, zero-energy modes, and the QRPA sum rule.

報告人簡介：

Dr. Nobuo Hinohara is an Assistant Professor at the Center for Computational Sciences, University of Tsukuba. He earned his Doctor of Science in Physics from Kyoto University, specializing in nuclear large-amplitude collective motion. He previously held research positions at RIKEN, the University of North Carolina, and the University of Tennessee, and was a visiting scholar at Michigan State University. His research focuses on nuclear structure theory, including nuclear density functional theory.

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報告人：李征征，北京大學

時間：10月16日（周四）15:50

單位：中國科學院理論物理研究所

地點：南樓6520

摘要：
Beta-decay half-lives set the time scale of the rapid neutron capture process (r-process), and therefore determine the production of the heavy elements in the universe. Currently, the data required by r-process mainly relies on theoretical calculations. The most commonly used model for beta-decay half-lives is proton-neutron quasiparticle random phase approximation (pnQRPA), which becomes numerically prohibitive in deformed nuclei. The implementation of finite amplitude method to pnQRPA enables its application for all nuclei without additional approximation. In this work, the pnQRPA based on the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc) is developed by implementing finite amplitude method. The deformation effects and isoscalar pairing effects on the low-lying Gamow-Teller transitions are discussed, and their influences on beta-decay half-lives are studied.

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報告人：孫磊，西湖大學理學院

時間：10月17日（周五）16:00

單位：中國科學技術大學精準智能化學重點實驗室

鏈接：

摘要：
分子量子比特框架（MQF）材料將穩定自由基集成于金屬有機框架或共價有機框架中，可通過對框架材料的結構構建來設計自由基所處的聲子和電磁環境，實現對其電子自旋動力學性質的精準調控，有望實現化學特異性量子傳感、光量子存儲等量子信息應用。本研究利用半醌式自由基構建一系列MQF材料，利用脈沖電子順磁共振（EPR）波譜探索其自旋動力學性質的構效關系，提出增強結構剛性和降低自旋濃度的設計原則，將室溫自旋弛豫時間和退相干時間分別提升至超過300 μs和5 μs。在手性MQF中觀測到反常自旋弛豫現象，基于磁場和客體分子對該現象的調控，提出手性結構導致非對稱自旋-聲子耦合，發現了一種新型準粒子—自旋-聲子極化子，并探索了其在加速量子比特初始化效率方面的應用。以上述MQF材料為量子探針，利用弛豫測試法和超精細光譜法，在室溫溶液相實現了對微觀粘度和核自旋的量子傳感，并通過對脈沖序列及其相循環方法的設計實現了量子相干性提升和量子傳感性能優化。

報告人簡介：

孫磊，吉林長春人。本科就讀于南京大學化學化工學院，2011年獲得學士學位。隨后加入麻省理工學院化學系Mircea Dinc?課題組，于2017年獲得無機化學博士學位。2017?2019年和2019?2021年先后在美國西北大學化學系Danna E. Freedman教授和阿貢國家實驗室納米材料中心Tijana Rajh高級研究員的指導下從事博士后研究。2019?2022年于佐治亞理工學院計算學院攻讀機器學習，獲得計算機科學碩士學位。2021年11月加入西湖大學理學院，兼任化學系和物理系助理教授，組建分子量子器件和量子信息實驗室。

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報告人：Leonardo Lessa，Perimeter Institute for Theoretical Physics

時間：10月17日（周五）9:00

單位：新加坡國立大學理學院物理系

鏈接：

摘要：

Symmetries and their anomalies are among the most powerful non-perturbative tools to characterize quantum many-body systems. Traditionally however, they have been limited to isolated systems, described by pure states. In this talk, we discuss how symmetries are a powerful constraint even when interactions with the environment are present. First, we show that topological order can survive as a long-range-entangled phase of matter even for mixed states. Crucially, this phase is characterized by emergent 1-form anomalous symmetries. Second, we address 0-form anomalies, which can appear at the boundary of SPT phases. There, we prove that strongly symmetric anomalous states exhibit long-range multipartite entanglement. Curiously, we find anomalous states possessing tripartite entanglement but no bipartite entanglement, an intrinsic feature of mixed states. Finally, if time permits, we discuss (non-anomalous) on-site symmetries. There, we find that thermal states with strong symmetries or superselection rules are generically entangled, which confirms previous results on specific symmetries and Hamiltonians.

封面圖片來源：https://www.guancha.cn/industry-science/2023_04_20_689181.shtml

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