1
|
Lee JH, Kim GW, Song I, Kim Y, Lee Y, Yoo SJ, Cho DY, Rhim JW, Jung J, Kim G, Kim C. Atomically Thin Two-Dimensional Kagome Flat Band on the Silicon Surface. ACS NANO 2024; 18:25535-25541. [PMID: 39213610 DOI: 10.1021/acsnano.4c05398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
In condensed matter physics, the Kagome lattice and its inherent flat bands have attracted considerable attention for their prediction and observation to host a variety of exotic physical phenomena. Despite extensive efforts to fabricate thin films of Kagome materials aimed at modulating flat bands through electrostatic gating or strain manipulation, progress has been limited. Here, we report the observation of a d-orbital hybridized Kagome-derived flat band in Ag/Si(111) 3 × 3 as revealed by angle-resolved photoemission spectroscopy. Our findings indicate that silver atoms on a silicon substrate form an unconventional distorted breathing Kagome structure, where a delicate balance in the hopping parameters of the in-plane d-orbitals leads to destructive interference, resulting in double flat bands. The exact quantum destructive interference mechanism that forms the flat band is uncovered in a rigorous manner that has not been described before. These results illuminate the potential for integrating metal-semiconductor interfaces on semiconductor surfaces into Kagome physics, particularly in exploring the flat bands of ideal 2D Kagome systems.
Collapse
Affiliation(s)
- Jae Hyuck Lee
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Gwan Woo Kim
- Department of Physics and HMC, Sejong University, Seoul 05006, Republic of Korea
| | - Inkyung Song
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Republic of Korea
| | - Yejin Kim
- Department of Physics, Jeonbuk National University, Jeonju 54896, Republic of Korea
| | - Yeonjae Lee
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Sung Jong Yoo
- Hydrogen·Fuel Cell Research Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
- Division of Energy & Environment Technology, KIST School, University of Science and Technology (UST), Daejeon 34113, Republic of Korea
- KHU-KIST Department of Converging Science and Technology, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Deok-Yong Cho
- Department of Physics, Jeonbuk National University, Jeonju 54896, Republic of Korea
| | - Jun-Won Rhim
- Department of Physics, Ajou University, Suwon 16499, Korea
- Research Center for Novel Epitaxial Quantum Architectures, Department of Physics, Seoul National University, Seoul 08826, Korea
| | - Jongkeun Jung
- Hydrogen·Fuel Cell Research Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Gunn Kim
- Department of Physics and HMC, Sejong University, Seoul 05006, Republic of Korea
- Center for Theoretical Physics (CTP), Seoul National University, Seoul 08826, Republic of Korea
| | - Changyoung Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| |
Collapse
|
2
|
Mo S, Seo J, Son SK, Kim S, Rhim JW, Lee H. Engineering Two-Dimensional Nodal Semimetals in Functionalized Biphenylene by Fluorine Adatoms. NANO LETTERS 2024; 24. [PMID: 38607382 PMCID: PMC11057037 DOI: 10.1021/acs.nanolett.4c00314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 04/10/2024] [Accepted: 04/10/2024] [Indexed: 04/13/2024]
Abstract
We propose a band engineering scheme on the biphenylene network, a newly synthesized carbon allotrope. We illustrate that the electronic structure of the biphenylene network can be significantly altered by controlling conditions affecting the symmetry and destructive interference of wave functions through periodic fluorination. First, we investigate the mechanism for the appearance of a type-II Dirac fermion in a pristine biphenylene network. We show that the essential ingredients are mirror symmetries and stabilization of the compact localized eigenstates via destructive interference. While the former is used for the band-crossing point along high symmetry lines, the latter induces highly inclined Dirac dispersions. Subsequently, we demonstrate the transformation of the biphenylene network's type-II Dirac semimetal phase into various Dirac phases such as type-I Dirac, gapped type-II Dirac, and nodal line semimetals through the deliberate disruption of mirror symmetry or modulation of destructive interference by varying the concentration of fluorine atoms.
Collapse
Affiliation(s)
- Seongjun Mo
- Department
of Physics, Konkuk University, Seoul 05029, Korea
| | - Jaeuk Seo
- Department
of Physics, Ajou University, Suwon 16499, Korea
- Department
of Physics, Korea Advanced Institute of
Science and Technology, Daejeon 34141, Korea
| | - Seok-Kyun Son
- Department
of Physics, Kyung Hee University, Seoul 02447, Republic of Korea
- Department
of Information Display, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Sejoong Kim
- University
of Science and Technology (UST), Gajeong-ro 217, Daejeon 34113, Korea
- Korea
Institute for Advanced Study, Hoegiro 85, Seoul 02455, Korea
| | - Jun-Won Rhim
- Research
Center for Novel Epitaxial Quantum Architectures, Department of Physics, Seoul National University, Seoul 08826, Korea
- Department
of Physics, Ajou University, Suwon 16499, Korea
| | - Hoonkyung Lee
- Department
of Physics, Konkuk University, Seoul 05029, Korea
- Research
Center for Novel Epitaxial Quantum Architectures, Department of Physics, Seoul National University, Seoul 08826, Korea
| |
Collapse
|
3
|
Song L, Gao S, Ma J, Tang L, Song D, Li Y, Chen Z. Multiple flatbands and localized states in photonic super-Kagome lattices. OPTICS LETTERS 2023; 48:5947-5950. [PMID: 37966759 DOI: 10.1364/ol.504794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 10/14/2023] [Indexed: 11/16/2023]
Abstract
We demonstrate multiple flatbands and compact localized states (CLSs) in a photonic super-Kagome lattice (SKL) that exhibits coexistence of singular and nonsingular flatbands within its unique band structure. Specifically, we find that the upper two flatbands of an SKL are singular-characterized by singularities due to band touching with their neighboring dispersive bands at the Brillouin zone center. Conversely, the lower three degenerate flatbands are nonsingular and remain spectrally isolated from other dispersive bands. The existence of such two distinct types of flatbands is experimentally demonstrated by observing stable evolution of the CLSs with various geometrical shapes in a laser-written SKL. We also discuss the classification of the flatbands in momentum space, using band-touching singularities of the Bloch wave functions. Furthermore, we validate this classification in real space based on unit cell occupancy of the CLSs in a single SKL plaquette. These results may provide insights for the study of flatband transport, dynamics, and nontrivial topological phenomena in other relevant systems.
Collapse
|
4
|
Feng Y, Liu Z, Liu F, Yu J, Liang S, Li F, Zhang Y, Xiao M, Zhang Z. Loss Difference Induced Localization in a Non-Hermitian Honeycomb Photonic Lattice. PHYSICAL REVIEW LETTERS 2023; 131:013802. [PMID: 37478430 DOI: 10.1103/physrevlett.131.013802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 05/25/2023] [Indexed: 07/23/2023]
Abstract
Non-Hermitian systems with complex-valued energy spectra provide an extraordinary platform for manipulating unconventional dynamics of light. Here, we demonstrate the localization of light in an instantaneously reconfigurable non-Hermitian honeycomb photonic lattice that is established in a coherently prepared atomic system. One set of the sublattices is optically modulated to introduce the absorptive difference between neighboring lattice sites, where the Dirac points in reciprocal space are extended into dispersionless local flat bands, with two shared eigenstates: low-loss (high-loss) one with fields confined at sublattice B (A). When these local flat bands are broad enough due to larger loss difference, the incident beam with its tangential wave vector being at the K point in reciprocal space is effectively localized at sublattice B with weaker absorption, namely, the commonly seen power exchange between adjacent channels in photonic lattices is effectively prohibited. The current work unlocks a new capability from non-Hermitian two-dimensional photonic lattices and provides an alternative route for engineering tunable local flat bands in photonic structures.
Collapse
Affiliation(s)
- Yuan Feng
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Zhenzhi Liu
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Fu Liu
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jiawei Yu
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Shun Liang
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Feng Li
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Yanpeng Zhang
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Min Xiao
- Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Zhaoyang Zhang
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| |
Collapse
|
5
|
He R, Liu P, Wang B, Fan J, Liu C. Doping-induced magnetism and magnetoelectric coupling in one-dimensional NbOCl 3 and NbOBr 3. Phys Chem Chem Phys 2023; 25:5244-5250. [PMID: 36723202 DOI: 10.1039/d2cp05823e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Low-dimensional multiferroic systems with magnetoelectric coupling have attracted considerable attention due to their important applications in high-density low-power storage. Based on the first-principles calculations, we demonstrated that the recently proposed one-dimensional (1D) ferroelectric materials NbOCl3 and NbOBr3 have good stabilities, and found that they can be easily separated from the bulk phase. Due to the flat band near the Fermi level, the itinerant ferromagnetism can be induced over a wide range of electron-doping concentrations, and it leads to the coexistence of ferroelectricity and ferromagnetism in 1D NbOX3 (X = Cl, Br) and finite-length nanochains. More interestingly, there is strong magnetoelectric coupling on finite-length nanochains, which is caused by the spontaneous electrical polarization and redistribution of magnetic carriers. In addition, magnetism also can be introduced by oxygen vacancies. We also analyzed the effects of doping concentration, strain, and length on ferroelectric polarization and magnetism. Our findings provide a way to design and search low-dimensional multiferroics.
Collapse
Affiliation(s)
- Ruiman He
- Institute for Computational Materials Science, Joint Center for Theoretical Physics (JCTP), School of Physics and Electronics, Henan University, Kaifeng, 475004, China.
| | - Pengyu Liu
- Institute for Computational Materials Science, Joint Center for Theoretical Physics (JCTP), School of Physics and Electronics, Henan University, Kaifeng, 475004, China.
| | - Bing Wang
- Institute for Computational Materials Science, Joint Center for Theoretical Physics (JCTP), School of Physics and Electronics, Henan University, Kaifeng, 475004, China.
| | - Jinbo Fan
- Institute for Computational Materials Science, Joint Center for Theoretical Physics (JCTP), School of Physics and Electronics, Henan University, Kaifeng, 475004, China.
| | - Chang Liu
- Institute for Computational Materials Science, Joint Center for Theoretical Physics (JCTP), School of Physics and Electronics, Henan University, Kaifeng, 475004, China.
| |
Collapse
|
6
|
Pan M, Zhang X, Zhou Y, Wang P, Bian Q, Liu H, Wang X, Li X, Chen A, Lei X, Li S, Cheng Z, Shao Z, Ding H, Gao J, Li F, Liu F. Growth of Mesoscale Ordered Two-Dimensional Hydrogen-Bond Organic Framework with the Observation of Flat Band. PHYSICAL REVIEW LETTERS 2023; 130:036203. [PMID: 36763396 DOI: 10.1103/physrevlett.130.036203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 11/18/2022] [Accepted: 12/16/2022] [Indexed: 06/18/2023]
Abstract
Flat bands (FBs), presenting a strongly interacting quantum system, have drawn increasing interest recently. However, experimental growth and synthesis of FB materials have been challenging and have remained elusive for the ideal form of monolayer materials where the FB arises from destructive quantum interference as predicted in 2D lattice models. Here, we report surface growth of a self-assembled monolayer of 2D hydrogen-bond (H-bond) organic frameworks (HOFs) of 1,3,5-tris(4-hydroxyphenyl)benzene (THPB) on Au(111) substrate and the observation of FB. High-resolution scanning tunneling microscopy or spectroscopy shows mesoscale, highly ordered, and uniform THPB HOF domains, while angle-resolved photoemission spectroscopy highlights a FB over the whole Brillouin zone. Density-functional-theory calculations and analyses reveal that the observed topological FB arises from a hidden electronic breathing-kagome lattice without atomically breathing bonds. Our findings demonstrate that self-assembly of HOFs provides a viable approach for synthesis of 2D organic topological materials, paving the way to explore many-body quantum states of topological FBs.
Collapse
Affiliation(s)
- Minghu Pan
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710119, China
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xin Zhang
- School of Physics, Northwest University, Xi'an, 710069, China
| | - Yinong Zhou
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, USA
| | - Pengdong Wang
- Vacuum Interconnected Nanotech Workstation, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123, China
| | - Qi Bian
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Hang Liu
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, USA
| | - Xingyue Wang
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710119, China
| | - Xiaoyin Li
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, USA
| | - Aixi Chen
- Vacuum Interconnected Nanotech Workstation, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123, China
| | - Xiaoxu Lei
- Vacuum Interconnected Nanotech Workstation, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123, China
| | - Shaojian Li
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhengwang Cheng
- School of Science and Hubei Engineering Technology Research Center of Energy Photoelectric Device and System, Hubei University of Technology, Wuhan 430068, China
| | - Zhibin Shao
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710119, China
| | - Haoxuan Ding
- School of Physics and Astronomy, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - Jianzhi Gao
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710119, China
| | - Fangsen Li
- Vacuum Interconnected Nanotech Workstation, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123, China
| | - Feng Liu
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, USA
| |
Collapse
|
7
|
Park W, Lee J, Han MJ, Wolska J, Pociecha D, Gorecka E, Seo MK, Choi YS, Yoon DK. Light-Driven Fabrication of a Chiral Photonic Lattice of the Helical Nanofilament Liquid Crystal Phase. ACS APPLIED MATERIALS & INTERFACES 2022; 14:4409-4416. [PMID: 35029362 DOI: 10.1021/acsami.1c19382] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A photonic lattice is an efficient platform for optically exploring quantum phenomena. However, its fabrication requires high costs and complex procedures when conventional materials, such as silicon or metals, are used. Here, we demonstrate a simple and cost-effective fabrication method for a reconfigurable chiral photonic lattice of the helical nanofilament (HNF) liquid crystal (LC) phase and diffraction grating showing wavelength-dependent diffraction with a rotated polarization state. Furthermore, the UV-exposed areas of the HNF film having chiral characteristics act as optical building blocks that induce resonant intensity modulation in the reflectance and transmittance modes and the optical rotation of the linear polarization. Our photonic lattice of the HNF can be an efficient platform for a chirality-embedded photonic lattice at a low cost.
Collapse
Affiliation(s)
- Wongi Park
- Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Jongmin Lee
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Moon Jong Han
- Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Joanna Wolska
- Faculty of Chemistry, University of Warsaw, Warsaw 02-089, Poland
| | - Damian Pociecha
- Faculty of Chemistry, University of Warsaw, Warsaw 02-089, Poland
| | - Ewa Gorecka
- Faculty of Chemistry, University of Warsaw, Warsaw 02-089, Poland
| | - Min-Kyo Seo
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Yun-Seok Choi
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Dong Ki Yoon
- Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- KAIST Institute for Nanocentury, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| |
Collapse
|
8
|
Xia S, Zhang Y, Li Z, Qin L, Yang C, Lu H, Zhang J, Zhao X, Zhu Z. Band evolution and Landau-Zener Bloch oscillations in strained photonic rhombic lattices. OPTICS EXPRESS 2021; 29:37503-37514. [PMID: 34808820 DOI: 10.1364/oe.441554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 10/19/2021] [Indexed: 06/13/2023]
Abstract
We investigate band evolution of chiral and non-chiral symmetric flatband photonic rhombic lattices by applying a strain along the diagonal direction, and thereby demonstrating Landau-Zener Bloch (LZB) oscillations in the presence of a refractive index gradient. The chiral and non-chiral symmetric rhombic lattices are obtained by adding a detuning to uniform lattices. For the chiral symmetric lattices, the middle flatband is perturbed due to the chiral symmetry breaking while a nearly flatband appears as the bottom band with the increase of strain-induced next-nearest-neighbor hopping. Consequently, LZB oscillations exhibit intriguing characteristics such as asymmetric energy transitions and almost complete suppression of the oscillations. Nevertheless, for the non-chiral symmetric lattices, flatband persists owing to the retained particle-hole symmetry and evolves into the bottom band. Remarkably, the band gap can be readily tuned, which allows controlling of the amplitude of Landau-Zener tunneling (LZT) rate and may lead to thorough LZT. Our analysis provides an alternative perspective on the generation of tunable flatband and may also bring insight to study the symmetry and topological characterization of the flatband.
Collapse
|
9
|
Hwang Y, Rhim JW, Yang BJ. Geometric characterization of anomalous Landau levels of isolated flat bands. Nat Commun 2021; 12:6433. [PMID: 34741062 PMCID: PMC8571270 DOI: 10.1038/s41467-021-26765-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 10/14/2021] [Indexed: 12/03/2022] Open
Abstract
According to the Onsager’s semiclassical quantization rule, the Landau levels of a band are bounded by its upper and lower band edges at zero magnetic field. However, there are two notable systems where the Landau level spectra violate this expectation, including topological bands and flat bands with singular band crossings, whose wave functions possess some singularities. Here, we introduce a distinct class of flat band systems where anomalous Landau level spreading (LLS) appears outside the zero-field energy bounds, although the relevant wave function is nonsingular. The anomalous LLS of isolated flat bands are governed by the cross-gap Berry connection that measures the wave-function geometry of multi bands. We also find that symmetry puts strong constraints on the LLS of flat bands. Our work demonstrates that an isolated flat band is an ideal system for studying the fundamental role of wave-function geometry in describing magnetic responses of solids. Landau levels are normally bounded by upper and lower band edges at zero magnetic field. Here, the authors predict a system with isolated flat bands, where anomalous Landau level spreading appears outside the zero-field energy bounds.
Collapse
Affiliation(s)
- Yoonseok Hwang
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul, 08826, Korea.,Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea.,Center for Theoretical Physics (CTP), Seoul National University, Seoul, 08826, Korea
| | - Jun-Won Rhim
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul, 08826, Korea. .,Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea. .,Department of Physics, Ajou University, Suwon, 16499, Korea.
| | - Bohm-Jung Yang
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul, 08826, Korea. .,Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea. .,Center for Theoretical Physics (CTP), Seoul National University, Seoul, 08826, Korea.
| |
Collapse
|
10
|
Román-Cortés D, Fadic G, Cid-Lara C, Guzmán-Silva D, Real B, Vicencio RA. Strain induced localization to delocalization transition on a Lieb photonic ribbon lattice. Sci Rep 2021; 11:21411. [PMID: 34725440 PMCID: PMC8560923 DOI: 10.1038/s41598-021-00967-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 10/20/2021] [Indexed: 11/09/2022] Open
Abstract
Ribbon lattices are kind of transition systems in between one and two dimensions, and their study is crucial to understand the origin of different emerging properties. In this work, we study a Lieb ribbon lattice and the localization-delocalization transition occurring due to a reduction of lattice distances (compression) and the corresponding flat band deformation. We observe how above a critical compression ratio the energy spreads out and propagates freely across the lattice, therefore transforming the system from being a kind of insulator into a conductor. We implement an experiment on a photonic platform and show an excellent agreement with the predicted phenomenology. Our findings suggest and prove experimentally the use of compression or mechanical deformation of lattices to switch the transport properties of a given system.
Collapse
Affiliation(s)
- Diego Román-Cortés
- Departamento de Física and Millenium Institute for Research in Optics-MIRO, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
| | - Guillermo Fadic
- Departamento de Física and Millenium Institute for Research in Optics-MIRO, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
| | - Christofer Cid-Lara
- Departamento de Física and Millenium Institute for Research in Optics-MIRO, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
| | - Diego Guzmán-Silva
- Departamento de Física and Millenium Institute for Research in Optics-MIRO, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
| | - Bastián Real
- Univ. Lille, CNRS, UMR 8523-PhLAM-Physique des Lasers Atomes et Molécules, 59000, Lille, France
| | - Rodrigo A Vicencio
- Departamento de Física and Millenium Institute for Research in Optics-MIRO, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile.
| |
Collapse
|
11
|
Ding L, Lin Z, Ke S, Wang B, Lu P. Non-Hermitian flat bands in rhombic microring resonator arrays. OPTICS EXPRESS 2021; 29:24373-24386. [PMID: 34614684 DOI: 10.1364/oe.431038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
We investigate the flat bands in a quasi-one-dimensional rhombic array composed of evanescently coupled microring resonators (MRRs) with non-Hermitian coupling. By changing the relative position of non-Hermitian coupling in each cell, we construct topologically trivial and nontrivial flat bands, where both the real and imaginary parts of energy bands become flat and coalesce into a single band. We show the nontrivial systems are able to support topological boundary modes isolated from the flat bulk bands although there is no band gap. The elusive topology of flat bands can be geometrically visualized by plotting the trajectories of their eigenvectors on Bloch sphere based on Majorana's stellar representation (MSR). Furthermore, we perform a full wave simulation and show the characteristics of flat bands, associated compact localized modes, and boundary modes are reflected from absorption spectra and field intensity profiles. The study may find potential applications in lasers, narrowband filters, and efficient light harvesting.
Collapse
|
12
|
He Y, Mao R, Cai H, Zhang JX, Li Y, Yuan L, Zhu SY, Wang DW. Flat-Band Localization in Creutz Superradiance Lattices. PHYSICAL REVIEW LETTERS 2021; 126:103601. [PMID: 33784152 DOI: 10.1103/physrevlett.126.103601] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 02/02/2021] [Indexed: 06/12/2023]
Abstract
Flat bands play an important role in diffraction-free photonics and attract fundamental interest in many-body physics. Here we report the engineering of flat-band localization of collective excited states of atoms in Creutz superradiance lattices with tunable synthetic gauge fields. Magnitudes and phases of the lattice hopping coefficients can be independently tuned to control the state components of the flat band and the Aharonov-Bohm phases. We can selectively excite the flat band and control the flat-band localization with the synthetic gauge field. Our study provides a room-temperature platform for flat bands of atoms and holds promising applications in exploring correlated topological materials.
Collapse
Affiliation(s)
- Yanyan He
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, Department of Physics, Zhejiang University, Hangzhou 310027, Zhejiang Province, China
| | - Ruosong Mao
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, Department of Physics, Zhejiang University, Hangzhou 310027, Zhejiang Province, China
| | - Han Cai
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, Department of Physics, Zhejiang University, Hangzhou 310027, Zhejiang Province, China
| | - Jun-Xiang Zhang
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, Department of Physics, Zhejiang University, Hangzhou 310027, Zhejiang Province, China
| | - Yongqiang Li
- Department of Physics, National University of Defense Technology, Changsha 410073, Hunan Province, China
| | - Luqi Yuan
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shi-Yao Zhu
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, Department of Physics, Zhejiang University, Hangzhou 310027, Zhejiang Province, China
| | - Da-Wei Wang
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, Department of Physics, Zhejiang University, Hangzhou 310027, Zhejiang Province, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
| |
Collapse
|