Related topics: physical review letters

Understanding room-temperature superconductivity

Room-temperature superconductors could transform everything from electrical grids to particle accelerators to computers, but researchers are still trying to understand how these materials function on the atomic level.

Clean doping strategy produces more responsive phototransistors

The library of two-dimensional (2D) layered materials keeps growing, from basic 2D materials to metal chalcogenides. Unlike their bulk counterparts, 2D layered materials possess novel features that offer great potential in ...

Spintronics: How an atom-thin insulator helps transport spins

An intermediate layer consisting of a few atoms is helping to improve the transport of spin currents from one material to another. Until now, this process involves significant losses. A team from Martin Luther University ...

Team creates map for production of eco-friendly metals

In work that could usher in more efficient, eco-friendly processes for the production of important metals like lithium, iron and cobalt, researchers from MIT and SLAC have mapped what is happening at the atomic level behind ...

Unlocking complex workings of the biological clock

Scientists want to increase their understanding of circadian rhythms, those internal 24-hour biological clock cycles of sleeping and waking that occur in organisms, ranging from humans to plants to fungi to bacteria. A research ...

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Perturbation theory (quantum mechanics)

In quantum mechanics, perturbation theory is a set of approximation schemes directly related to mathematical perturbation for describing a complicated quantum system in terms of a simpler one. The idea is to start with a simple system for which a mathematical solution is known, and add an additional "perturbing" Hamiltonian representing a weak disturbance to the system. If the disturbance is not too large, the various physical quantities associated with the perturbed system (e.g. its energy levels and eigenstates) can, from considerations of continuity, be expressed as 'corrections' to those of the simple system. These corrections, being 'small' compared to the size of the quantities themselves, can be calculated using approximate methods such as asymptotic series. We can therefore study the complicated system based on our knowledge of the simpler one.

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