Original author(s) | Andrea Marini |
---|---|
Developer(s) | Davide Sangalli, Claudio Attaccalite, Andrea Ferretti, Henrique Miranda, Myrta Gruning, Conor Hogan, Daniele Varsano, Dario A. Leon, Fulvio Paleari, Igancio Alliati, Nicola Spallanzani, Nalabothula Muralidhar, Elena Molteni, Alberto Guandalini, Pedro Melo, Ryan McMillan, Fabio Affinito, Alejandro Molina-Sanchez |
Initial release | 2008 |
Stable release | 5.2 / 31 August 2023 |
Repository | github |
Written in | Fortran, C |
Operating system | Unix, Unix-like |
Platform | x86, x86-64 |
Available in | English |
Type | Many-body theory |
License | GPL |
Website | www |
Yambo is a computer software package for studying many-body theory aspects of solids and molecule systems. [1] [2] It calculates the excited state properties of physical systems from first principles, e.g., from quantum mechanics law without the use of empirical data. It is an open-source software released under the GNU General Public License (GPL). However the main development repository is private and only a subset of the features available in the private repository are cloned into the public repository and thus distributed. [3]
Yambo can calculate:
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Yambo can treat molecules and periodic systems (both metallic an insulating) in three dimensions (crystalline solids) two dimensions (surfaces) and one dimension (e.g., nanotubes, nanowires, polymer chains). It can also handle collinear (i.e., spin-polarized wave functions) and non-collinear (spinors) magnetic systems.
Typical systems are of the size of 10-100 atoms, or 10-400 electrons, per unit cell in the case of periodic systems.
Yambo relies on many-body perturbation theory and time-dependent density functional theory. [13] [14] Quasiparticle energies are calculated within the GW approximation [15] for the self energy. Optical properties are calculated either by solving the Bethe–Salpeter equation [16] [17] or by using the adiabatic local density approximation within time-dependent density functional theory.
Yambo uses a plane waves basis set to represent the electronic (single-particle) wavefunctions. Core electrons are described with norm-conserving pseudopotentials. The choice of a plane-wave basis set enforces the periodicity of the systems. Isolated systems, and systems that are periodic in only one or two directions can be treated by using a supercell approach. For such systems Yambo offers two numerical techniques for the treatment of the Coulomb integrals: the cut-off [18] and the random-integration method.
The Yambo team provides a wiki web-page with a list of tutorials and lecture notes. On the yambo web-site there is also a list of all thesis done with the code.
Part of the YAMBO code is kept under a private repository. These are the features implemented and not yet distributed:
Mott insulators are a class of materials that are expected to conduct electricity according to conventional band theories, but turn out to be insulators. These insulators fail to be correctly described by band theories of solids due to their strong electron–electron interactions, which are not considered in conventional band theory. A Mott transition is a transition from a metal to an insulator, driven by the strong interactions between electrons. One of the simplest models that can capture Mott transition is the Hubbard model.
In physics, topological order is a kind of order in the zero-temperature phase of matter. Macroscopically, topological order is defined and described by robust ground state degeneracy and quantized non-abelian geometric phases of degenerate ground states. Microscopically, topological orders correspond to patterns of long-range quantum entanglement. States with different topological orders cannot change into each other without a phase transition.
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Oleg Sushkov is a professor at the University of New South Wales and a leader in the field of high temperature super-conductors. Educated in Russia in quantum mechanics and nuclear physics, he now teaches in Australia.
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Marvin Lou Cohen is an American–Canadian theoretical physicist. He is a physics professor at the University of California, Berkeley. Cohen is a leading expert in the field of condensed matter physics. He is widely known for his seminal work on the electronic structure of solids.
Steven R. White is a professor of physics at the University of California, Irvine. He is a condensed matter physicist who specializes in the simulation of quantum systems. He graduated from the University of California, San Diego; he then received his Ph.D. at Cornell University, where he was a shared student with Kenneth Wilson and John Wilkins.
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Patrick A. Lee is a professor of physics at the Massachusetts Institute of Technology (MIT).
Xiao-Gang Wen is a Chinese-American physicist. He is a Cecil and Ida Green Professor of Physics at the Massachusetts Institute of Technology and Distinguished Visiting Research Chair at the Perimeter Institute for Theoretical Physics. His expertise is in condensed matter theory in strongly correlated electronic systems. In Oct. 2016, he was awarded the Oliver E. Buckley Condensed Matter Prize.
David Matthew Ceperley is a theoretical physicist in the physics department at the University of Illinois Urbana-Champaign or UIUC. He is a world expert in the area of Quantum Monte Carlo computations, a method of calculation that is generally recognised to provide accurate quantitative results for many-body problems described by quantum mechanics.
In physics, the plasmaron was proposed by Lundqvist in 1967 as a quasiparticle arising in a system that has strong plasmon-electron interactions. In the original work, the plasmaron was proposed to describe a secondary peak in the photoemission spectral function of the electron gas. More precisely it was defined as an additional zero of the quasi-particle equation . The same authors pointed out, in a subsequent work, that this extra solution might be an artifact of the used approximations:
We want to stress again that the discussion we have given of the one-electron spectrum is based on the assumption that vertex corrections are small. As discussed in the next section recent work by Langreth [29] shows that vertex corrections in the core electron problem can have a quite large effect on the form of satellite structures, while their effect on the quasi particle properties seems to be small. Preliminary investigations by one of us (L.H.) show similar strong vertex effects on the conduction band satellite. The details of the plasmaron structure should thus not be taken very seriously.
The toric code is a topological quantum error correcting code, and an example of a stabilizer code, defined on a two-dimensional spin lattice. It is the simplest and most well studied of the quantum double models. It is also the simplest example of topological order—Z2 topological order (first studied in the context of Z2 spin liquid in 1991). The toric code can also be considered to be a Z2 lattice gauge theory in a particular limit. It was introduced by Alexei Kitaev.
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Erio Tosatti is an Italian theoretical physicist active at the International School for Advanced Studies (SISSA), and at the Abdus Salam International Centre for Theoretical Physics (ICTP), both in Trieste, Italy. He is a broad-scope theorist who carried out research on a wide range of condensed matter physics phenomena. His early work dealt with optical properties, electron energy loss, theory of excitons and nonlocal dielectric response in solids, including layer crystals such as graphite and semiconductors; charge- and spin-density-waves; surface physics in all its aspects, particularly reconstruction, roughening and melting, also in clusters; the prediction the Berry phase in fullerene; the first calculated STM map of graphite, now a standard in the field; matter at extreme pressures: carbon, oxygen, hydrogen, CO2, iron at earth core conditions, water and ammonia at deep planetary conditions, pressure-induced insulator-metal transitions in layer compounds like MoS2. In nanophysics, he and his group predicted helical structures of metal nanowires; the spontaneous magnetism of metal nanocontacts, including the electronic circumstances for normal or ferromagnetic Kondo effect therein. His and his collaborator's theory of strongly correlated superconductivity was recently confirmed in compounds such as Cs3C60. Pioneering papers on quantum annealing are now basic to current developments in quantum computing. More recently he moved on to the theory of nanofriction, a field where he obtained the ERC Advanced Grant MODPHYSFRICT 2013–2019, and subsequently, as co-PI with an experimental group, another ERC Advanced Grant ULTRADISS 2019-2024. More details of his current and past research activity can be found here.
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