Article
Astronomy & Astrophysics
Claudio Bonanno, Massimo D'Elia, Francesca Margari
Summary: The topological susceptibility of 2D CPN-1 models is expected to diverge as N approaches 2. This divergence is caused by the dominance of instantons of arbitrarily small size, making it difficult to detect through numerical lattice simulations. By studying the behavior of the model with a fixed volume in dimensionless lattice units, we confirm the divergence of the topological susceptibility of the 2D CP1 model using a nonperturbative approach.
Review
Physics, Applied
Oliver Breunig, Yoichi Ando
Summary: Topological insulators are unique materials that result in unconventional quantum phenomena. To observe these phenomena experimentally, sophisticated devices are required. This Technical Review discusses various physics effects that can be observed in carefully fabricated devices, including topological superconductivity, quantum anomalous Hall states, spintronic functionalities and topological mesoscopic physics.
NATURE REVIEWS PHYSICS
(2022)
Article
Physics, Applied
Arman Rashidi, Robert Kealhofer, Alexander C. Lygo, Susanne Stemmer
Summary: In this study, we investigate the dephasing mechanisms in topological materials by fabricating gated nanoscale mesas on thin films of cadmium arsenide. We observe two independent types of conductance oscillations related to the applied magnetic field and gate voltage. Varying the nanostructure dimensions allows us to distinguish different scenarios of previously reported similar oscillations. Our conclusion is that these conductance oscillations are not a signature of topological boundary states, but rather universal conductance fluctuations. These findings provide valuable insights for interpreting electronic quantum interference in mesoscopic devices made from topological materials.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Multidisciplinary
Haedong Park, Sang Soon Oh
Summary: This paper discusses the sign flipping issue of non-abelian topological charges in phononic and photonic topological semimetals, and confirms through numerical calculation and visualization that this flipping does not cause any inconsistency in building the quaternion group.
NEW JOURNAL OF PHYSICS
(2022)
Article
Multidisciplinary Sciences
Ann-Kathrin Stock, Paul Wendiggensen, Filippo Ghin, Christian Beste
Summary: High-dose alcohol intoxication reduces cognitive control, particularly inhibition. Research shows that alcohol-induced impairments in reactive control can be compensated by increased proactive control. Therefore, it is important to consider both immediate effects and compensatory mechanisms when studying the impact of alcohol on cognitive control.
SCIENTIFIC REPORTS
(2023)
Article
Physics, Multidisciplinary
Sungjong No, Seungsang Oh, Hyungkee Yoo
Summary: This paper explores the application of knots and embedded graphs in simulating polymer chains, focusing on the theta curve motif in a circular protein with internal bridges. Qualitative results of nontrivial theta-curves and Brunnian theta-curves are obtained using the lattice stick number, with lower bounds presented for both types of curves.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Review
Psychology, Multidisciplinary
Justin M. Power
Summary: This article discusses the contributions of William Stokoe to sign language historical linguistics, and provides an overview of the field's development and the challenges it faces. It also explores the issues related to understanding sign language relationships and sign cognacy, and suggests future research directions.
FRONTIERS IN PSYCHOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Kun Luo, Hao Geng, Li Sheng, Wei Chen, D. Y. Xing
Summary: The study demonstrates that the spatial configurations of hinge states in 3D HOTIs can be clearly revealed by using interfering loops composed of two basic magnetic fluxes. The frequency components of conductance oscillations are universally related, facilitating the exploration of the AB effect in 3D HOTIs.
Article
Materials Science, Multidisciplinary
Ruchi Saxena, Eytan Grosfeld, Sebastian E. de Graaf, Tobias Lindstrom, Floriana Lombardi, Oindrila Deb, Eran Ginossar
Summary: We analyze the confinement of electronic surface states in a model of a topological insulator nanowire. We show that intentional backscattering can be induced in the presence of a nanowire constriction and propose a geometry involving two constrictions that form effective barriers for the formation of a quantum dot. By analyzing the noninteracting electronic transport through the device, we demonstrate how externally applied magnetic flux and electrostatic gates can control the spectrum of the quantum dot and the electronic transport through the surface states of the model device.
Article
Engineering, Electrical & Electronic
Chunhua Geng, Hua Sun, Syed A. Jafar
Summary: The study combines the principles of treating interference as noise with the topological interference management framework to address a TIM-TIN problem for multilevel interference management. An analytical baseline approach and a distributed numerical algorithm called ZEST are proposed to handle the TIM-TIN problem, demonstrating superior sum-rate performance and fast convergence. The convergence of the algorithm highlights the duality of the TIM-TIN problem in terms of generalized degrees-of-freedom (GDoF).
IEEE TRANSACTIONS ON COMMUNICATIONS
(2021)
Article
Physics, Applied
Lalit Pandey, Rahul Gupta, Amir Khan, Nanhe Kumar Gupta, Soumyarup Hait, Nakul Kumar, Vireshwar Mishra, Nikita Sharma, Peter Svedlindh, Sujeet Chaudhary
Summary: In this study, magnetic heterostructures consisting of Bi2Te3 (BT) and Co60Fe20B20 (CFB) were fabricated using the DC magnetron sputtering technique to investigate the temperature-dependent spin pumping. The results revealed that the effective spin-mixing conductance is significantly affected by the contribution of two-magnon scattering (TMS) and it increases with decreasing temperature when TMS is absent. Furthermore, magneto-transport measurements indicated that the surface coherence length of BT is consistent with the temperature-dependent effective spin-mixing conductance. The enhancement of effective mixing conductance was found to be correlated with the increased contribution of the topological surface states (TSSs) as evaluated using the weak-anti-localization effect. This study provides insights into the temperature-dependent spin dynamics in sputtered BT/CFB heterostructures and serves as a guide for further exploration of such bilayers for topological-based spintronic applications.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Xu Zhang, Gaopei Pan, Bin-Bin Chen, Heqiu Li, Kai Sun, Zi Yang Meng
Summary: We demonstrate that quantum Monte Carlo (QMC) simulations can be used to accurately simulate magic-angle twisted bilayer graphene (TBG) and obtain a precise phase diagram and dynamical properties. The simulations reveal a thermodynamic transition separating the metallic state and a C = 1 correlated Chern insulator-topological Mott insulator (TMI) at the chiral limit and filling v = 1, as well as a pseudogap spectrum slightly above the transition temperature. These results are consistent with recent experimental findings in nonaligned TBG devices.
Article
Physics, Multidisciplinary
Wujun Shi, Benjamin J. Wieder, Holger L. Meyerheim, Yan Sun, Yang Zhang, Yiwei Li, Lei Shen, Yanpeng Qi, Lexian Yang, Jagannath Jena, Peter Werner, Klaus Koepernik, Stuart Parkin, Yulin Chen, Claudia Felser, B. Andrei Bernevig, Zhijun Wang
Summary: The study demonstrates that (TaSe4)(2)I is a Weyl semimetal with 24 pairs of Weyl nodes at room temperature, and also exhibits an established charge-density wave instability. The charge-density wave in (TaSe4)(2)I couples the bulk Weyl points and opens a bandgap, providing a pathway for exploring the interplay of correlations and topology in a solid-state material.
Article
Chemistry, Multidisciplinary
Rawana Yagan, Arash Mousavi Cheghabouri, Mehmet C. Onbasli
Summary: Synthetic antiferromagnetically coupled (SAF) multilayers provide a large range of material parameters that stabilize skyrmions. The current-driven SAF skyrmions have velocities 3-10 times greater than ferromagnetic skyrmions, and the current density needed to drive SAF skyrmions is significantly lower, resulting in reduced Joule heating.
NANOSCALE ADVANCES
(2023)
Article
Materials Science, Multidisciplinary
Weiyan Lin, Yang Feng, Yongchao Wang, Zichen Lian, Hao Li, Yang Wu, Chang Liu, Yihua Wang, Jinsong Zhang, Yayu Wang, Xiaodong Zhou, Jian Shen
Summary: The beauty of the quantum Hall effect lies in the metrological precision of Hall resistance quantization, which is derived from topological edge states. In this study, we investigate the relationship between quantization breakdown and edge states in the MnBi2Te4 system using conventional transport and real space conductivity mapping. Our experimental results demonstrate the existence of topological edge states during quantization breakdown, which can cause the breakdown due to their dissipative and diffusive nature.
Article
Physics, Particles & Fields
Yuya Tanizaki, Mithat Unsal
JOURNAL OF HIGH ENERGY PHYSICS
(2020)
Article
Physics, Particles & Fields
Tin Sulejmanpasic, Yuya Tanizaki, Mithat Unsal
JOURNAL OF HIGH ENERGY PHYSICS
(2020)
Article
Physics, Multidisciplinary
Aleksey Cherman, Theodore Jacobson, Yuya Tanizaki, Mithat Unsal
Article
Physics, Particles & Fields
Naohisa Sueishi, Syo Kamata, Tatsuhiro Misumi, Mithat Unsal
JOURNAL OF HIGH ENERGY PHYSICS
(2020)
Article
Physics, Particles & Fields
Mendel Nguyen, Yuya Tanizaki, Mithat Unsal
Summary: The study examines a 3D lattice gauge theory with semi-Abelian gauge group, calculating mass gaps and string tensions using a monopole-gas description. It finds that the string tensions deviate from the N-ality rule and provide more information about the representations of the gauge group. The presence of non-invertible topological lines from the original Abelian theory explains this deviation, which is broken by adding W-bosons leading to the emergence of the N-ality rule in the deep infrared regime.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Naohisa Sueishi, Syo Kamata, Tatsuhiro Misumi, Mithat Unsal
Summary: The study focuses on exact-WKB analysis for quantum mechanics in a periodic potential with N minima on S-1. It provides a quantization condition consistent with known conjectures and mixed anomaly, and shows the closed nature of the resurgent structure in Hilbert subspaces.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Mithat Unsal
Summary: The paper discusses a class of quantum field theories and quantum mechanics, coupled with Z(N) topological QFTs to classify non-perturbative effects in the original theory. The coupling of SU(N) Yang-Mills theory with Z(N) TQFT and the importance of PSU(N) bundle and lift configurations are highlighted, providing a new perspective and solutions for the strong coupling regime.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Multidisciplinary
Cihan Pazarba, Mithat Unsal
Summary: In the Polyakov model, a nonperturbative mass gap is formed at leading-order semiclassics by instanton effects. However, a third-order effect in semiclassics introduces an imaginary ambiguous contribution to the mass gap, which is troublesome for the original analysis. By compactifying the Polyakov model to quantum mechanics using a background ???t Hooft flux, the ambiguity in three-instanton sector is proven to cancel against the ambiguity in the Borel resummation of the perturbation theory, providing a large-order asymptotics.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Particles & Fields
Mithat Unsal
Summary: In this work, symmetry graded state sums for various non-supersymmetric theories are constructed and studied. The specific properties of these theories, such as the existence of the color-flavor center symmetry and the spontaneous breaking of chirality symmetry, are investigated.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Multidisciplinary
Yuya Tanizaki, Mithat Unsal
Summary: We construct an anomaly-preserving compactification of 4D gauge theories down to 2D by turning on 't Hooft flux through T-2. This provides a new framework to analyze nonperturbative properties and we give a semiclassical description based on the center vortex. We conjecture an adiabatic connection between weak-coupling vacuum structure on small T-2 x R-2 and strong-coupling regime on R-4.
PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS
(2022)
Article
Physics, Particles & Fields
Cihan Pazarbasi, Mithat Unsal
Summary: In this study, we construct a compactification of the Polyakov model to quantum mechanics on T-2 x R, which retains the non-perturbative aspects of field theory even at small areas. By introducing a background magnetic flux, we observe the appearance of N-degenerate vacua and flux changing instantons on the small torus. The reduction of the Polyakov model to quantum mechanics is compared with deformed Yang-Mills, and critical points at infinity in the semiclassical expansion are discussed.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Yuya Tanizaki, Mithat Unsal
Summary: This study investigates quantum chromodynamics with two-index symmetric or anti-symmetric quarks (QCD(Sym/ASym)) on small R-2 x T-2 with a suitable magnetic flux. The 't Hooft anomaly of these theories is discussed, and it is claimed that discrete chiral symmetry should be completely spontaneously broken to satisfy the anomaly matching condition. The T-2 compactification with magnetic flux preserves the 't Hooft anomaly, and the 2D effective theory is constrained by the same anomaly as the 4D QCD(Sym/ASym). The spontaneous breakdown of chiral symmetry is demonstrated using the dilute gas of center vortices, confirming the prediction of the 't Hooft anomaly. It is also found that each vacuum maintains the charge conjugation symmetry, providing support for the nonperturbative large-N orientifold equivalence between QCD(Sym/ASym) and N = 1 supersymmetric SU(N) Yang-Mills theory.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Astronomy & Astrophysics
Mendel Nguyen, Yuya Tanizaki, Mithat Unsal
Summary: In 2D Yang-Mills theory, exact Casimir scaling leads to infinitely many string tensions due to nonpropagating gluons. The richness in the spectrum of string tensions, seemingly mysterious from ordinary symmetry considerations, cannot be explained by finite center symmetry. By introducing a noninvertible 1-form symmetry, a discrepancy between dynamics and kinematics is resolved, with potential implications for Yang-Mills theories in 3D and 4D.
Article
Astronomy & Astrophysics
Takuya Kanazawa, Mithat Unsal
Article
Astronomy & Astrophysics
Aleksey Cherman, Syo Kamata, Thomas Schafer, Mithat Unsal