時間とスペクトルの指紋は,超高速全相関スピンスイッチング

S Schlauderer¹, C Lange², S Baierl¹

¹Department of Physics, University of Regensburg, Regensburg, Germany.

Nature

|May 17, 2019

まとめ

研究者は,反鉄磁性チューリウム・オートフェライトにおけるコヘランス・スピン・スイッチングのためのテラヘルツ電磁パルスを実証した. 量子スピン状態を低損失で高速で制御できる未来の情報技術です

科学分野:

量子制御
スピントロニクス
凝縮物質物理学

背景:

将来の情報技術にはより速く低損失の量子制御が必要です
物質の新たな状態と電子加速の進歩を促しました
量子スピンの状態を効率的に切り替えることは重要なことですが難しいことです

研究の目的:

テラヘルツパルスを使って,潜在的な障壁の上でスピンの一貫した方向性を実証する.
このスイッチングプロセス中のスピンダイナミクスを観察し,特徴づけます.
テラヘルツで動作するスケーラブルなスピンデバイスの可能性を調査する.

主な方法:

強いテラヘルツの電磁パルスを使って 1ピコ秒の長さで
コップリングスピンは,局所的に強化されたテラヘルツ電場を持つ反鉄磁性チューリウムオーソフェライト (TmFeO3) です.
テラヘルツの電波を集めるためにオーダーメイドのアンテナを使います

主要な成果:

潜在的障壁の上にスピンの一貫した方向を観測した.
段階転移と非対称な共振分裂を含むスピンダイナミクスの時間的およびスペクトル指紋を特定した.
外部磁気バイアスによって切り替え可能な状態が選択できることを示した.

結論:

テラヘルツパルスは効率的で低分散のコヒーレントスピンスイッチングを可能にします.
観察された現象は,スピンダイナミクスを理解するための特徴を提供します.
このアプローチは,テラヘルツ周波数で動作するスケーラブルなスピントロニックデバイスの開発に有望です.

さらに関連する動画

05:57

Blood Flow Imaging with Ultrafast Doppler

Published on: October 14, 2020

8.4K

08:22

Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization

Published on: August 6, 2018

7.3K

関連する概念動画

01:22

Switching of BJT

818

Switching behavior in Bipolar Junction Transistors (BJTs) is a fundamental aspect utilized in various electronic circuits, particularly for digital logic applications like switches and amplifiers. In a typical switching circuit, a BJT alternates between cut-off and saturation modes, corresponding to the "off" and "on" states, respectively, thus behaving like an ideal switch.
Cut-off Mode ("Off" State): In this state, both the emitter-base and collector-base junctions are...

818

01:03

IR Frequency Region: Fingerprint Region

1.9K

IR spectra are divided into two main regions: the diagnostic region and the fingerprint region. The diagnostic region of the spectrum lies above 1500 cm−1. The absorptions resulting from single-bond vibrations of the N–H, C–H, and O–H stretch at higher wavenumbers and appear on the left side of the spectrum. The stretching absorptions of the C≡C and C≡N occur between 2100–2300 cm−1. In contrast, those arising from stretching absorptions of the...

1.9K

01:08

Spin–Spin Coupling Constant: Overview

1.5K

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...

1.5K

01:08

NMR Spectroscopy: Spin–Spin Coupling

3.0K

The spin state of an NMR-active nucleus can have a slight effect on its immediate electronic environment. This effect propagates through the intervening bonds and affects the electronic environments of NMR-active nuclei up to three bonds away; occasionally, even farther. This phenomenon is called spin–spin coupling or J-coupling. Coupling interactions are mutual and result in small changes in the absorption frequencies of both nuclei involved. While nuclei of the same element are involved...

3.0K

01:17

Spin–Spin Coupling: One-Bond Coupling

1.4K

Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...

1.4K

01:20

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

1.6K

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...