In atomic physics and chemistry, an atomic electron transition is an electron changing from one energy level to another within an atom or artificial atom. The time scale of a quantum jump has not been measured experimentally. However, the Franck–Condon principle binds the upper limit of this parameter to the order of attoseconds.
Ionization is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons, often in conjunction with other chemical changes. The resulting electrically charged atom or molecule is called an ion. Ionization can result from the loss of an electron after collisions with subatomic particles, collisions with other atoms, molecules, electrons, positrons, protons, antiprotons and ions, or through the interaction with electromagnetic radiation. Heterolytic bond cleavage and heterolytic substitution reactions can result in the formation of ion pairs. Ionization can occur through radioactive decay by the internal conversion process, in which an excited nucleus transfers its energy to one of the inner-shell electrons causing it to be ejected.
An attosecond is a unit of time in the International System of Units (SI) equal to 10−18 or 1⁄1 000 000 000 000 000 000 of a second.
Matter waves are a central part of the theory of quantum mechanics, being half of wave–particle duality. At all scales where measurements have been practical, matter exhibits wave-like behavior. For example, a beam of electrons can be diffracted just like a beam of light or a water wave.
The quantum Zeno effect is a feature of quantum-mechanical systems allowing a particle's time evolution to be slowed down by measuring it frequently enough with respect to some chosen measurement setting.
In quantum physics, the Stern–Gerlach experiment demonstrated that the spatial orientation of angular momentum is quantized. Thus an atomic-scale system was shown to have intrinsically quantum properties. In the original experiment, silver atoms were sent through a spatially-varying magnetic field, which deflected them before they struck a detector screen, such as a glass slide. Particles with non-zero magnetic moment were deflected, owing to the magnetic field gradient, from a straight path. The screen revealed discrete points of accumulation, rather than a continuous distribution, owing to their quantized spin. Historically, this experiment was decisive in convincing physicists of the reality of angular-momentum quantization in all atomic-scale systems.
Photoionization is the physical process in which an ion is formed from the interaction of a photon with an atom or molecule.
Attosecond physics, also known as attophysics, or more generally attosecond science, is a branch of physics that deals with light-matter interaction phenomena wherein attosecond photon pulses are used to unravel dynamical processes in matter with unprecedented time resolution.
In magnetism, a nanomagnet is a nanoscopic scale system that presents spontaneous magnetic order (magnetization) at zero applied magnetic field (remanence).
Paul Bruce Corkum is a Canadian physicist specializing in attosecond physics and laser science. He holds a joint University of Ottawa–NRC chair in attosecond photonics. He also holds academic positions at Texas A&M University and the University of New Mexico. Corkum is both a theorist and an experimentalist.
In physics, a trojan wave packet is a wave packet that is nonstationary and nonspreading. It is part of an artificially created system that consists of a nucleus and one or more electron wave packets, and that is highly excited under a continuous electromagnetic field. Its discovery as one of significant contributions to the quantum mechanics was awarded the 2022 Wigner Medal for Iwo Bialynicki-Birula
The timeline of quantum mechanics is a list of key events in the history of quantum mechanics, quantum field theories and quantum chemistry.
Double ionization is a process of formation of doubly charged ions when laser radiation or charged particles like electrons, positrons or heavy ions are exerted on neutral atoms or molecules. Double ionization is usually less probable than single-electron ionization. Two types of double ionization are distinguished: sequential and non-sequential.
Nam Chang-hee is a South Korean plasma physicist. Nam is specializing in the exploration of relativistic laser-matter interactions using femtosecond PW lasers. Currently he is professor of physics at Gwangju Institute of Science and Technology and director of the Center for Relativistic Laser Science as a part of the Institute for Basic Science (IBS).
Charusita Chakravarty was an Indian academic and scientist. She was a professor of chemistry at the Indian Institute of Technology, Delhi since 1999. In 2009 she was conferred Shanti Swarup Bhatnagar Prize for Science and Technology in the field of chemical science. In 1999, she received B.M. Birla Science Award. She was an Associate Member of the Centre for Computational Material Science, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore.
Quantum microscopy allows microscopic properties of matter and quantum particles to be measured and imaged. Various types of microscopy use quantum principles. The first microscope to do so was the scanning tunneling microscope, which paved the way for development of the photoionization microscope and the quantum entanglement microscope.
Bidyendu Mohan Deb is an Indian theoretical chemist, chemical physicist and a professor at the Indian Institute of Science Education and Research, Kolkata (IISER). he is known for his studies in theoretical chemistry and chemical physics. He is an elected fellow of the International Union of Pure and Applied Chemistry, The World Academy of Sciences, Indian National Science Academy and the Indian Academy of Sciences. The Council of Scientific and Industrial Research, the apex agency of the Government of India for scientific research, awarded him the Shanti Swarup Bhatnagar Prize for Science and Technology, one of the highest Indian science awards, in 1981, for his contributions to chemical sciences.
Collaborative Computational Project Q (CCPQ) was developed in order to provide software which uses theoretical techniques to catalogue collisions between electrons, positrons or photons and atomic/molecular targets. The 'Q' stands for quantum dynamics. This project is accessible via the CCPForge website, which contains numerous other projects such as CCP2 and CCP4. The scope has increased to include atoms and molecules in strong laser fields, low-energy interactions of antihydrogen with small atoms and molecules, cold atoms, Bose–Einstein condensates and optical lattices. CCPQ gives essential information on the reactivity of various molecules, and contains two community codes R-matrix suite and MCTDH wavepacket dynamics.
Purushottam Chakraborty is an Indian physicist who is one of the renowned experts in materials analysis using ion beams and secondary ion mass spectrometry (SIMS).
Attosecond chronoscopy are measurement techniques for attosecond-scale delays of atomic and molecular single photon processes like photoemission and photoionization. Ionization-delay measurements in atomic targets provide information about the timing of the photoelectric effect, resonances, electron correlations, and transport.
