電子穴再衝突の実験的観測

B Zaks¹, R B Liu, M S Sherwin

¹Department of Physics, University of California at Santa Barbara, Santa Barbara, California 93106, USA.

Nature

|March 31, 2012

まとめ

研究者らは,半導体量子井戸で高次元のサイドバンド生成を観測し,電子穴再衝突がエネルギー的な光放射を生成する新しい現象である. この発見は,超高速光通信に潜在的応用がある.

科学分野:

固体物理学固体物理学とは
量子光学とは,量子光学である.
非線形光学とは,非線形光学である.

背景:

高度ハーモニック生成 (HHG) は,原子核との電子再衝突を伴うもので,エネルギッシュな光子を生成します.
固体における電子穴のペアであるエクシトンは,理論的には同様の再衝突現象を示すと予測されていた.
高級サイドバンド生成 (HSG) は,エキシトン電子穴再衝突の結果として予測されました.

研究の目的:

半導体量子井戸における高次元のサイドバンド生成を実験的に観察し,特徴づけること.
レーザーの極化と強度に対するHSGの依存性を調査する.
超高速光調節と光通信における潜在的な応用を探求する.

主な方法:

半導体量子井戸で,近赤外線レーザー (f ((NIR)) を使用してエキシトンが生成されました.
強い低周波テラヘルツ (THz) レーザー (f ((THz)) は,刺激子内の電子穴再衝突を誘導した.
周波数 f ((NIR) + 2nf ((THz)) のサイドバンドを特定し,定量化するために,放射スペクトルを分析した.

主要な成果:

半導体量子井戸で高次元のサイドバンド生成が成功裏に観察されました.
サイドバンドは,18度目まで検出されました (n=9),より高い順序では弱い強度の衰退がありました.
この現象は,線形に偏移したTHz放射線では最も強く,円形に偏移した放射線では存在しない.

結論:

実験的観測は,固体における高次元のサイドバンド生成の予測を裏付けている.
結果は,超高速光調節の可能性のある非混乱的相互作用メカニズムを示しています.
この研究は,新しいテラビット速度の光通信技術への道を開きます.

さらに関連する動画

09:00

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser

Published on: June 28, 2018

11:27

Single-Molecule Förster Resonance Energy Transfer Methods for Real-Time Investigation of the Holliday Junction Resolution by GEN1

Published on: September 18, 2019

関連する概念動画

01:19

Thomson's e/m Experiment

In a beam of charged particles created by a heated cathode, the particles move at different speeds. However, many applications need a beam with uniform particle speeds. An arrangement known as a velocity selector uses electric and magnetic fields to pick particles with a particular speed from the beam.
A particle with charge q, speed v, and mass m enters an area from the top, where the magnetic and electric fields are perpendicular both to the particle's motion and to one another. The magnetic...

00:54

Electron Behavior

Overview
Electrons are negatively charged subatomic particles that are attracted to an orbit around the positively-charged nucleus of an atom. They reside in locations that are associated with energy levels called shells and are further organized into sub-shells and orbitals within each shell.
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the...

01:09

Electron Behavior

Electrons are negatively charged subatomic particles attracted to and orbit around the positively-charged nucleus of an atom. They reside in spaces associated with energy levels called shells and are further organized into subshells and orbitals within each shell.
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus have less energy,...

02:32

The de Broglie Wavelength

In the macroscopic world, objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle; it will continue traveling in a straight line unless it collides with another ball, or it is acted on by some other force, such as friction. The ball has a well-defined position and velocity or well-defined momentum, p = mv, which is defined by mass m and velocity v at any given moment. This is the typical...

01:27

π Electron Effects on Chemical Shift: Overview

An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0, resulting in...

01:18

Electron Orbital Model

Orbitals are the areas outside of the atomic nucleus where electrons are most likely to reside. They are characterized by different energy levels, shapes, and three-dimensional orientations. The location of electrons is described most generally by a shell or principal energy level, then by a subshell within each shell, and finally, by individual orbitals found within the subshells.
The first shell is closest to the nucleus, and it has only one subshell with a single spherical orbital called the...

関連する実験動画