张松波，合肥实验室研究员，中科大未来技术学院博士生导师，国家级海外青年人才项目（2023年）、中科院百人计划入选者。2012年本科毕业于中山大学，2016年博士毕业于香港大学。博士毕业后在德国维尔茨堡大学和瑞士苏黎世大学开展博士后研究。2023年加入中科大微尺度物质科学国家研究中心，后转聘到合肥实验室。

课题组研究领域是凝聚态物理理论，主要研究新型量子物相 (如拓扑绝缘体/超导体、量子霍尔效应、高阶拓扑物态等)，探讨其中新奇的量子效应、输运特性，以及在量子计算和电子器件等方面的应用。目前在相关领域已经取得多项创新成果，在 Nature Physics、Nature Materials、Physics Review Letters和Nature Commun.等期刊发表论文30多篇。

本课题组诚聘博士后 (待遇优厚长期有效)，欢迎对凝聚态理论感兴趣的学生加入（欢迎咨询和发送申请至邮箱：songbozhang@ustc.edu.cn）

Research interests and highlights

1. Unconventional antiferromagnets.

1-1) We show that proximity-induced Cooper pairs in altermagnets acquire finite center-of-mass momentum, despite zero net magnetization, leading to measurable phenomena such as periodic oscillations in the pairing correlation, 0-π transitions in Josephson junctions, large-oblique dominant transfer trajectories of Cooper pairs, and anomalous Fraunhofer pattern. [Nature Commun. 2024]

1-2) We propose employing the Coulomb drag to probe altermagnetism. We find that transverse currents can be dragged in the passive layer, leading to Hall drag effects even without spin-orbit coupling. All the drag effects of altermagnets have unique angle dependence, which can be measured in a multi-terminal setup to serve as signatures for altermagnetism. [arXiv:2412:13927] 

2. Topological phenomena in non-Hermitian systems.

2-1) We study the Hatano-Nelson model in presence of repulsive nearest-neighbor interactions. At half-filling, we find two 𝒫𝒯 phase transitions, as interaction strength increases. Away from half-filling, the many-body spectrum shows nontrivial point gaps, indicating the skin effect of extensive many-body eigenstates under open boundaries. [PRB 2022] We extend our theory to spinful systems and propose the non-Hermitian Mott skin effect. [PRL 2024]

2-2) We show that the second-order skin effect is robust and can even be enhanced by magnetic fields. [PRL 2023, Editors' Suggestions] Our theory has been applied to experiments. [e.g., APL 2024]

3. Topological states of matter and their unique transport 

3-1) We propose a 2D shifted CDW phase and show that its fully gapped bulk possesses topological properties that give rise to edge modes, exhibiting duality to the chiral edge modes of Chern insulators. [PRL 2023]. We work with experimental collaborators to implement our prediction in Ta₂Se₈I [Nature Physics 2024]. 

3-2) We find the super-resonant transport of Dirac surface states and its resulting quantum oscillations under in-plane magnetic fields. [PRL 2021] Our theory has been applied to the HgTe experiment by Molenkamp's group in Germany [NL 2023]. 

3-3) We develop a scattering approach to study QH/superconductor/QH junctions based on 2D Dirac semimetals and propose two setups where CAR is highly tunable and can reach unity probability. [PRL 2019] 

3-4) We derive analytically the topological invariant of QSHIs under perpendicular magnetic fields and show that QSHIs in HgTe and InAs/GaSb quantum wells can sustain large magnetic fields. [PRB 2014] We reveal that in these quantum wells, the Dirac point of edge states is pulled to be close to and even buried in the bulk valence bands when the system is in a deeply inverted regime. [PRB 2018] Our results provide plausible explanations for the experimental observations on the robust quantum edge transport of QSHIs subjected to strong magnetic fields.

3-5) We present exact solutions of the edge states of Landau levels in topological insulator thin films with open boundary conditions, and provide an intuitive edge-state picture to fully understand QH and QSH effects of the surface electrons. [SR 2015]. Our theory has been implemented in experiments [e.g., PRL 2023]. 

4. Higher-Order Topological States of Matter

4-1) Quantum computation based on second-order topological superconductors (SOTSs). We propose a generic model for SOTSs and demonstrate the exotic features of Majorana zero modes (Majoranas). We construct the fundamental fusion principles of the Majoranas, conceive different setups and present concrete protocols to exchange and fuse the Majoranas for non-Abelian braiding and holonomic quantum gate operations. [PRR 2020] We put forward a feasible scheme to realize networks that allow to nucleate and braid Majoranas in an all-electrical manner without fine-tuning.  [PRB 2020]

4-2) Detections and functionalities. We propose 0-π Josephson transitions as novel experimental signatures to detect 2D SOTSs and identify the SOTS-based Josephson junction as a fully electric platform to nucleate or annihilate Majorana bound states. [PRR 2020] We find that higher-order Weyl superconductors can be realized in odd-parity topological superconductors by periodic driving. [PRB 2021] We propose an intrinsic 3D Fabry-Perot type interferometer that offers feasible transport signatures to detect SOTIs. [PRL 2022, Cover paper]. Our theory have been applied to the Bi4Br4 experiment by Hasan's group at Princeton [Nature physics 2024].   

4-3) Disorder problem. Random flux is commonly believed to be incapable of driving full metal-insulator transitions. Surprisingly, we show that random flux can after all induce a full metal-insulator transition in the 2D Su-Schrieffer-Heeger model. The resulting insulating phase can even be a higher-order topological insulator. [PRB 2022, Editor's Suggestions]

5. Transport Properties of Weyl and Dirac Semimetals

5-1) Magnetotransport and the chiral anomaly. We develop a comprehensive magnetotransport theory of Weyl semimetals (WSM) in the strong field limit. [PRB 2015, NJP 2016] Our theory has been extensively applied to explain experiments [e.g., NC 2016, SA 2022]. We provide a systematic study of magnetic oscillations of acoustic phonons in WSM. [PRB 2020]. This theory has also been applied to experiments [e.g., NC 2022].

5-2) Transport in hybrid structures. We find that a chirality Josephson current emerges under Zeeman fields even without phase difference across the junction and embodies a novel quantum anomaly associated with a Z2 symmetry at low energies. [PRL 2018] We find that in an extended regime, the zero-bias differential conductance of a time-reversal symmetric WSM/SC junction acquires the universal value of e²/h per channel. [PRB 2018]  In NSN junctions based on time-reversal broken WSM, we observe a net spin polarization of Cooper pairs due an electron population imbalance between the two chirality. [PRB 2019]

近期论文（完整论文列表请见 谷歌学术）

[1] S.-B. Zhang#, L.-H. Hu#, & T. Neupert, Finite-momentum Cooper pairing in proximitized altermagnets, Nature Commun. 15, 1801 (2024).

[2] M. Litskevich*, M. Hossain*, S.-B. Zhang* et al., Boundary modes of a charge density wave state in a topological material, Nature Physics 20, 1254 (2024).

[3] M. Bahari, S.-B. Zhang, C. Li, S. Choi, P. Rüßmann, C. Timm, & B. Trauzettel, Helical topological superconducting pairing at finite excitation energies, Phys. Rev. Lett. 132, 266201 (2024).

[4] T. Yoshida, S.-B. Zhang, T. Neupert, & N. Kawakami, Non-Hermitian Mott skin effect, Phys. Rev. Lett. 132, 266201 (2024).

[5] C.-A. Li, B. Trauzettel, T. Neupert, & S.-B. Zhang#, Enhancement of second-order non-Hermitian skin effect by magnetic fields, Phys. Rev. Lett. 131, 116601 (2023) [Editors‘ Suggestion].

[6] S.-B. Zhang#, X. Liu, M. Hossain, J.-X. Yin, Z. Hasan, & T. Neupert#, Emergent edge modes in shifted quasi-one-dimensional charge density waves, Phys. Rev. Lett. 130, 106203 (2023).

[7] S.-B. Zhang#, C.-A. Li, F. Peña-Benitez, P. Surówka, R. Moessner, L. Molenkamp, & B. Trauzettel, Super-resonant transport of topological surface states subjected to in-plane magnetic fields, Phys. Rev. Lett. 127, 076601 (2021).

[8] C.-A. Li#, S.-B. Zhang#, J. Li, & B. Trauzettel, Higher-order Fabry-Pérot interferometer from topological hinge states, Phys. Rev. Lett. 127, 026803 (2021) [Cover Article].

[9] S.-B. Zhang and B. Trauzettel, Perfect crossed Andreev reflection in Dirac hybrid junctions in the quantum Hall regime, Phys. Rev. Lett. 122, 257701 (2019).

[10] S.-B. Zhang, J. Erdmenger, and B. Trauzettel, Chirality Josephson current due to a novel quantum anomaly in inversion-asymmetric Weyl semimetals, Phys. Rev. Lett. 121, 226604 (2018).