解决电子离开道屏障的时间
Dror Shafir1, Hadas Soifer, Barry D Bruner
1Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel.
Nature
|May 19, 2012
概括
研究人员使用探头激光测量了电子道的退出时间. 这一突破精确地跟踪了道挖掘后的电子动态,这对于超快的科学和秒速实验至关重要.
科学领域:
- 量子力学就是量子力学.
- 超快的科学超快的科学
- 原子和分子物理学 原子和分子物理学
背景情况:
- 电子道化是一个由强烈的激光场启动的基本量子过程.
- 亚秒科学研究了亚秒 (10^-18秒) 时间尺度上的电子动力学.
- 将道化与屏障外的电子动力学联系起来仍然是量子力学的一个关键挑战.
研究的目的:
- 开发一种方法来测量电子退出道屏障的精确时间.
- 在激光诱导道挖掘后立即调查电子动态.
- 为解决超快的多电子重排列提供一个工具.
主要方法:
- 利用一个弱探头场来引导道电子横向.
- 监测电子离子再次相遇时发出的每秒钟的光闪.
- 从特定的分子轨道测量离子化时间的微妙延迟.
主要成果:
- 成功测量了电子从道屏障的退出时间.
- 通过检测二氧化碳分子中的电离延迟,表现出高灵敏度.
- 验证了一种用于探测道挖掘后电子动态的新方法.
结论:
- 开发的方法精确地确定了电子道的退出时间.
- 这种技术对于推进一秒钟实验和理解超快动态是必不可少的.
- 为原子和分子中复杂的电子重新排列提供了一个解决时间的一般工具.
更多相关视频
11:33All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
Published on: January 19, 2018
10:28Probing the Structure and Dynamics of Interfacial Water with Scanning Tunneling Microscopy and Spectroscopy
Published on: May 27, 2018
相关概念视频
The Uncertainty Principle
Werner Heisenberg considered the limits of how accurately one can measure properties of an electron or other microscopic particles. He determined that there is a fundamental limit to how accurately one can measure both a particle’s position and its momentum simultaneously. The more accurate the measurement of the momentum of a particle is known, the less accurate the position at that time is known and vice versa. This is what is now called the Heisenberg uncertainty principle. He mathematically...
The Energies of Atomic Orbitals
In an atom, the negatively charged electrons are attracted to the positively charged nucleus. In a multielectron atom, electron-electron repulsions are also observed. The attractive and repulsive forces are dependent on the distance between the particles, as well as the sign and magnitude of the charges on the individual particles. When the charges on the particles are opposite, they attract each other. If both particles have the same charge, they repel each other.
Atomic Nuclei: Types of Nuclear Relaxation
Nuclear relaxation restores the equilibrium population imbalance and can occur via spin–lattice or spin–spin mechanisms, which are first-order exponential decay processes.
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers energy to a nearby...
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers energy to a nearby...
Deactivation Processes: Jablonski Diagram
Luminescence, the emission of light by a substance that has absorbed energy, is a process that involves the interaction of molecules with light. The energy-level diagram, or Jablonski diagram, is a graphical representation of these interactions, illustrating the various states and transitions a molecule can undergo. In a typical Jablonski diagram, the lowest horizontal line represents the ground-state energy of the molecule, which is usually a singlet state. This state represents the energies...
Fermi Level Dynamics
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...
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...
Carrier Generation and Recombination
Carrier generation is the process by which electron-hole pairs (EHPs) are created within the semiconductor. In direct-bandgap semiconductors, such as gallium arsenide (GaAs), this occurs efficiently when energy absorption prompts valence electrons to leap into the conduction band, leaving behind holes.
This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum.
Indirect generation involves an...
This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum.
Indirect generation involves an...
