Related Experiment Video
Updated: May 15, 2025
15:25
Design and Characterization Methodology for Efficient Wide Range Tunable MEMS Filters
Published on: February 4, 2018
6.1K
Symmetry-Related Large-Area Corner Mode with a Tunable Mode Area and Stable Frequency
Zhongfu Li1,2, Shiqi Li3, Bei Yan4
1The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, Peoples's Republic of China.
Physical Review Letters
|April 7, 2025
Summary
We introduce a novel topological corner mode in lattices with tunable area and stable frequency. This symmetry-protected mode, observed in a 2D photonic system, advances higher-order topology research.
Area of Science:
- Condensed Matter Physics
- Topological Photonics
Background:
- Collective modes in lattices exhibit intriguing phenomena.
- Large-area modes typically have small level spacings, while stable frequency modes are spatially confined.
Purpose of the Study:
- To theoretically propose and experimentally demonstrate a novel symmetry-related topological corner mode.
- To achieve a tunable mode area and stable frequency for this mode.
- To explore its potential applications in photonic devices.
Main Methods:
- Theoretical proposal of a symmetry-related large-area topological corner mode.
- Experimental demonstration in a two-dimensional (2D) photonic system.
- Hybridization of homogeneous Dirac point mode and in-gap topological corner modes.
Main Results:
- Demonstration of a large-area topological corner mode with tunable area and stable frequency.
- Observation of unique chirality linked to chiral symmetry.
- Experimental validation of the mode's robustness against structural disorders.
Conclusions:
- The findings advance higher-order topology research by transitioning to hybridized multilattice systems.
- The demonstrated mode shows potential for applications, particularly in vertical-cavity surface-emitting lasers.
Related Concept Videos
01:08IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
853
Identical bonds within a polyatomic group can stretch symmetrically (in-phase) or asymmetrically (out-of-phase). Similar to hydrogen bonding, these vibrations also influence the shape of the IR peak. Generally, asymmetric stretching frequencies are higher than symmetric stretching frequencies. For example, primary amines exhibit two distinct IR peaks between 3300–3500 cm−1 corresponding to the symmetric and asymmetric N-H stretching, while secondary amines exhibit a single...
853
01:04Modes of Standing Waves: II
812
The starting point for expressing the modes of standing waves is understanding the boundary conditions that the waves must follow. The boundary conditions are derived from the physical understanding of how the standing waves are sustained, that is, how the vibrating particles of the medium behave at the boundaries imposed on them.
For a tube open at one end and closed at the other filled with air, the modes are such that there is always an antinode at the open end and a node at the closed end....
For a tube open at one end and closed at the other filled with air, the modes are such that there is always an antinode at the open end and a node at the closed end....
812
01:30Oscillations In An LC Circuit
2.1K
An idealized LC circuit of zero resistance can oscillate without any source of emf by shifting the energy stored in the circuit between the electric and magnetic fields. In such an LC circuit, if the capacitor contains a charge q before the switch is closed, then all the energy of the circuit is initially stored in the electric field of the capacitor. This energy is given by
2.1K
01:22MOSFET: Enhancement Mode
248
Enhancement-mode MOSFETs are pivotal components in electronics, distinguished by their capacity to act as highly efficient switches. They are part of the larger family of metal-oxide Semiconductor Field-Effect Transistors (MOSFETs). They are available in two types: p-channel and n-channel, each tailored to specific polarity operations.
In their basic form, enhancement-mode MOSFETs are typically non-conductive when the gate-source voltage (Vgs) is zero. This default 'off' state means no...
In their basic form, enhancement-mode MOSFETs are typically non-conductive when the gate-source voltage (Vgs) is zero. This default 'off' state means no...
248
01:21Properties of Fourier series II
125
Time scaling of signals is a crucial concept in signal processing that affects the Fourier series representation without altering its coefficients. The process modifies the fundamental frequency, thereby changing how the series represents the signal over time. This principle is essential in various applications, including audio and image processing, where signal manipulation is frequent. Understanding function symmetries is fundamental to simplifying the Fourier series.
A function f(t) is...
A function f(t) is...
125
01:26Linear Approximation in Frequency Domain
79
Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar.
In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear....
In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear....
79