ダイラックコーンからの例外的な点の産卵リング

Bo Zhen¹, Chia Wei Hsu^1,2, Yuichi Igarashi^1,3

¹Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.

Nature

|September 10, 2015

まとめ

研究者は実験的に

科学分野:

光学について
凝縮物質物理学
量子力学

背景:

ダイラックの円はグラフェンやトポロジカル・イソレータのような素材に独特の電子特性を有しています
特殊な点 (対称時間対称性の破裂点) は,開かれたシステムで異常な現象を引き起こす.
非ヘルミシアン波動によるディラク円と例外的な点との間には理論的な関連がある.

研究の目的:

ディラック・コーンの変形によって"例外的なリング"の形成を実験的に実証する.
帯状構造の変形における開かれたシステムにおける放射線の役割を調査する.
ダイラック・コーンの物理を光子系の例外的な点と結びつけるために

主な方法:

フォトニック・クリスタル・スレブの製造と特徴付け
帯状構造を測定するために,角度で決定された反射測定を使用します.
変形と例外的なリング形成を特定するために複雑な固有値を分析します.

主要な成果:

フォトニック・クリスタル・スラブにおける特殊なリングの実験的実現
偶然の変性によるディラック円帯構造を観察した.
複雑な固有値の変形は,異なった放射線率のために例外のリングで囲まれた平らな帯に.
オープンシステムでの放射線は損失と利益の効果を模倣することが示されました.

結論:

特殊指輪の実験的な作成は,ディラクの円と特殊点の間の理論的なリンクを確認します.
オープンシステムにおける異なった放射線量は物理的性質を根本的に変化させ損失と利益に類似します
この研究は,光子やその他のオープンシステムにおける異質な現象の探索に新しい道を開きます.

さらに関連する動画

12:57

Resonance Fluorescence of an InGaAs Quantum Dot in a Planar Cavity Using Orthogonal Excitation and Detection

Published on: October 13, 2017

9.7K

11:19

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels

Published on: July 4, 2016

11.2K

関連する概念動画

01:20

Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)

1.9K

Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...

1.9K

01:07

Gravitational Potential Energy for Extended Objects

2.1K

Consider a system comprising several point masses. The coordinates of the center of mass for this system can be expressed as the summation of the product of each mass and its position vector divided by the total mass:

2.1K

01:08

Spin–Spin Coupling Constant: Overview

1.6K

In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...

1.6K

01:25

Divergence and Curl of Electric Field

7.6K

The divergence of a vector is a measure of how much the vector spreads out (diverges) from a point. For example, an electric field vector diverges from the positive charge and converges at the negative charge. The divergence of an electric field is derived using Gauss's law and is equal to the charge density divided by the permittivity of space. Mathematically, it is expressed as

7.6K

01:12

Fermi Level Dynamics

1.0K

The vacuum level denotes the energy threshold required for an electron to escape from a material surface. It is usually positioned above the conduction band of a semiconductor and acts as a benchmark for comparing electron energies within various materials.
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...

1.0K

01:14

π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds

2.0K

In aromatic compounds, such as benzene, the circulation of (4n + 2) π-electrons sets up a diamagnetic or diatropic ring current around the perimeter of the molecule. This current induces a magnetic field that opposes the external field inside the ring and reinforces it on the outside. The protons in benzene are deshielded and exhibit high chemical shifts in the range 6.5–8.5 ppm. The shielding effect at the center of the ring is evident in complex aromatic molecules, such as...