2025 Postdoctoral Frontier Symposium in Physics and Astronomy

Session

Condensed Matter

25 Sept 2025, 08:50

Tsung-Dao Lee Institute/N1F-N102 - Smart Classroom (Tsung-Dao Lee Institute)

9. Geometry, nematicity and transport in strained multi-Weyl semimetals

Ms Varsha Subramanyan

25/09/2025, 09:00

The minimal coupling of strain to Dirac and Weyl semimetals, and its modeling as a pseudo-gauge field has been extensively studied, resulting in several proposed topological transport signatures. However this insight does not carry over to Weyl semimetals of higher winding number, also known as multi-Weyl semimetals. Using the double-Weyl semimetal as an illustrative example, it is seen that...

6. Pathway to Chiral Conformal Field Theory and its realization via Cavity QED

Mr Chenan Wei (AI Alikhanyan National Science Laboratory)

25/09/2025, 09:30

We explore an integrable deformation of the spin-1/2 Heisenberg spin chain by leveraging its inherent conserved quantities. Starting with the isotropic (XXX) model, we identify the scalar chirality operator as one of its higher conserved charges. This operator, which breaks both time-reversal and parity symmetries, serves as the deformation term. Adding this chiral term to the Hamiltonian...

21. Imaging excitons of 2D semiconductors in momentum space by tr-ARPES

Mr XING ZHU (Okinawa Institute of Science and Technology)

25/09/2025, 10:30

Excitons - quasiparticles formed by coulomb-bounded electron-hole pairs, play a critical role in the optical response of 2D semiconductors. In monolayer Transition Metal Dichalcogenides (TMDCs) – prototypical 2D semiconductors, the interplay of spin and valley degrees of freedom gives rise to a complex excitonic landscape with significant contributions from the dark excitons which are hidden...

46. Interfacial magnetic spin Hall effect in van der Waals heterostructure

Ms Yudi Dai (Nanjing University)

25/09/2025, 11:00

The spin Hall effect (SHE) allows efficient generation of spin polarization or spin current through charge current and plays a crucial role in the development of spintronics. While SHE typically occurs in non-magnetic materials and is time-reversal even, exploring time-reversal-odd (T-odd) SHE, which couples SHE to magnetization in ferromagnetic materials, offers a new charge-spin conversion...

42. High Symmetric Sites Induced Unprecedented Ultra-Large-Period Moiré Lattice in Twisted Trilayer MoS2

Ms Tiantian Zhang (北京师范大学)

25/09/2025, 11:30

Twisted trilayer (Tt) transition metal dichalcogenides with their multiple rotational degrees of freedom offer unprecedented opportunities for the formation of large-wavelength moiré superlattices to maximize the effect of correlated behaviors. However, precisely stacking trilayer structures to realize ultra-large-wavelength moiré superlattices with a deep moiré potential remains a significant...

18. Understanding the dissipative behavior of superconducting resonators under variable bath temperature and readout power

Mr Zhenyuan Sun (Tsinghua University)

25/09/2025, 14:00

Superconducting microwave resonators, developed extensively in the context of Kinetic Inductance Detectors (KIDs), have great potential in astronomical detection due to their multiplexibility, high sensitivity, and ultra-low-noise performance. These detectors rely on sharp resonance curves characterized by high-quality factors (Q factors), which are critical for precise signal readout....

34. Symmetry-protected many-body states in superconducting quantum circuits

Mr Yi Shi (University College London)

25/09/2025, 14:30

We propose an interacting many-body spin model with nearest-neighbor and next-nearest neighbor couplings, where the two lowest eigenstates form a qubit manifold that is protected by symmetry from both relaxation and dephasing caused by local perturbations. We map the spin model to a superconducting circuit and show that such a circuit can reach coherence times exceeding several milliseconds in...

37. The competition between two irreducible representations that leads to re-emergent BTRS superconducting state under uniaxial stress and type 1.5 superconductivity

Mr Anton Talkachov (KTH Royal Institute of Technology)

25/09/2025, 15:30

We consider a general microscopic model describing a square (rectangular after distortion) lattice with nearest-neighbor interaction potential. We study the stress-induced splitting between $U(1)$ and $\mathbb{Z}_2$ superconducting critical temperatures. We find that broken time-reversal symmetry (BTRS) $s+id$ state generally has decreasing critical temperature under strain. However, in some...

80. Observation of quantum vortex core fractionalization and skyrmion formation in superconductor

Mr Quanxin Hu (TDLI)

25/09/2025, 16:00

One of the fundamental properties of a superconductor is expulsion of magnetic field. The only known exception was when they form a special type of topological defect: quantum vortices, which consist of a core singularity with circulating currents. The London’s quantization condition implies that there is one core singularity per quantum of magnetic flux in single-component superconductors....

81. Design, implementation and testing of a Shot Noise Scanning Tunneling Microscopy System

Mr Hongyuan Chen (李政道研究所)

25/09/2025, 16:30

The shot-noise scanning tunneling microscopy (SN-STM) is an emerging breakthrough in scanning probe techniques, achieving unprecedented atomic-scale resolution in shot-noise measurements to directly resolve the effective charge of tunneling carriers. This presentation will first introduce the fundamental physics of shot noise and its unique applications in quantum transport characterization,...

31. Cavity-modified quantum Hall phases

Mr Dalin Borici (Université Paris Cité)

26/09/2025, 09:00

Quantum vacuum fluctuations are usually negligible in solid-state systems due to their minimal strength. They have traditionally been linked to phenomena such as spontaneous emission and the Casimir effect. Recent advances in cavity engineering, however, allow for extreme compression of the photonic mode volume, enhancing considerably the vacuum electric field strength and driving light–matter...

82. Topological Phase Manipulation through Light–Matter Coupling in Cavities

Mr Liu Yang (TDLI)

26/09/2025, 09:30

We investigate how quantum fluctuations in cavities can modify the topological properties of materials such as graphene and quantum Hall (QH) systems. First, building on recent theoretical and experimental advances, we analyze the coupling between QH states and cavity modes with both linear and circular polarizations. Using a combination of microscopic and hydrodynamic approaches, we...

27. Detecting entanglement with transport measurement in weakly interacting and fluctuating systems

Mr Zhenhua Zhu (Tsinghua University)

26/09/2025, 10:30

Measuring entanglement entropy in interacting, multipartite systems remains a significant experimental challenge. We address this challenge by developing a protocol to measure von Neumann entropy (VNE) and mutual information in quantum transport systems with both many-body interactions and multiple subsystems. Our analysis indicates that the vital connection between VNE and two-point...

51. Non-Hermitian Fermi-Dirac Distribution and Applications in Quantum Transport

Mr Pei-Xin Shen (Institute of Physics, Polish Academy of Sciences)

26/09/2025, 11:00

In this talk, I will introduce the theory of persistent current transport in non-Hermitian quantum systems, building on the foundation of Hermitian superconducting-normal-superconducting junctions. I will then extend the system to incorporate dissipation using non-Hermitian quantum Hamiltonians. By employing Green’s function formalism, I will show the emergence of a non-Hermitian Fermi-Dirac...

11. Tricritical Kibble-Zurek scaling in Rydberg atom ladders

Mr Hanteng Wang (Tsinghua University)

26/09/2025, 11:30

The Kibble--Zurek (KZ) mechanism has been extensively studied in various second-order phase transitions, yet the case of tricriticality---the point where second-order phase transition lines terminate---remains experimentally elusive. Here, we theoretically propose probing KZ scaling at tricritical points using Rydberg atom arrays arranged as two- and three-leg ladders, which realize the...

64. Measurement-driven quantum advantages in shallow circuits

Mr Chenfeng Cao (FU Berlin)

26/09/2025, 14:00

Quantum advantage schemes probe the boundary between classically simulatable quantum systems and those that computationally go beyond this realm. Here, we introduce a constant-depth measurement-driven approach for efficiently sampling from a broad class of dense instantaneous quantum polynomial-time circuits and associated Hamiltonian phase states, previously requiring polynomial-depth unitary...

14. Grain Boundaries in Unconventional Superconductors: Vision Transformer–Enabled Coherent Diffraction Imaging

Mr Jialun Liu (UCL)

26/09/2025, 14:30

Grain boundaries and domain walls govern connectivity, pinning, and dissipation in unconventional superconductors, yet their internal 3D strain fields are difficult to quantify non-destructively. We combine Bragg Coherent Diffraction Imaging (BCDI) with a physics-informed Vision Transformer using Fourier-aware attention to achieve robust phase retrieval in the multidomain regime. The model...

84. Braiding Non-Abelian Anyons on Programmable Superconducting Processors

Mr Zheng-Zhi Sun (Tsinghua University)

26/09/2025, 15:00

Non-Abelian anyons are exotic quasiparticle excitations hosted by certain topologically-ordered phases of matter. They are the building blocks of topological quantum computing. In this talk, I will first give a brief introduction to non-Abelian anyons and then report two recent experimental quantum digital simulation of braiding non-Abelian anyons on programable superconducting processors. In...