Category archives: Quantum physics

Breakdown of the free electron gas concept for electronic stopping

Breakdown of the free electron gas concept for electronic stopping

Condensed matterMaterialsQuantum physics

By DIPC

There is a variable that is relevant for such seemingly different fields as outer space exploration , nanotechnology , fusion research , or medicine. And that is electronic stopping, its precise knowledge important for the understanding of space weathering, ion beam patterning, plasma-wall interactions, or radiation therapy, respectively. When ions propagate in matter, they are […]

Validating the existence of a new phase of matter, the exciton condensate

Validating the existence of a new phase of matter, the exciton condensate

Condensed matterMaterialsQuantum physics

By DIPC

According to how the electronic band theory is usually explained, solids can be classified as insulators, semiconductors, or metals. But, actually, there is another kind of solid between semiconductors and metals, the semimetals. In insulators and semiconductors the filled valence band is separated from an empty conduction band by a band gap, in metals there […]

A new benchmark for any future models of solid-state photoemission

A new benchmark for any future models of solid-state photoemission

Condensed matterMaterialsPhysicsQuantum physics

By DIPC

In 1882, Heinrich Hertz devoted himself to the study of electromagnetism, including the recent and still generally unappreciated work of Maxwell. Two years later he began his famous series of experiments with electromagnetic waves. During the course of this work, Hertz discovered the photoelectric effect, which has had a profound influence on modern physics. The […]

Strong donor-acceptor coupling does not require covalent bonding

Strong donor-acceptor coupling does not require covalent bonding

ChemistryCondensed matterMaterialsQuantum physics

By DIPC

Interfacial electron transfer constitutes the key step in the conversion of solar energy into electricity and fuels. Required for fast and efficient charge separation, strong donor−acceptor interaction is typically achieved through covalent chemical bonding…or not. Experiences with donor−acceptor molecular diads and triads, conjugated polymers, and DNA, leads to the expectation that a covalent bonding is […]

Topological Quantum Chemistry, the band theory of solids is now complete

Topological Quantum Chemistry, the band theory of solids is now complete

Condensed matterMaterialsQuantum physics

By DIPC

Extended and refined by Bloch and others during the 1930s, Bloch’s theory, known as the band theory of solids, accounts very well for the conducting behaviour of materials. When atoms are joined together into a crystal, each of the individual quantum states of the atoms joins with the corresponding states in other (identical) atoms in […]

Materials for raising the temperature of the quantized anomalous Hall and magnetoelectric effects

Materials for raising the temperature of the quantized anomalous Hall and magnetoelectric effects

Condensed matterMaterialsPhysicsQuantum physics

By DIPC

Topological insulators are electronic materials that have a bulk band gap like an ordinary insulator but have conducting states on their edge or surface. The conducting surface is not what makes topological insulators unique, but the fact that it is protected due to the combination of spin-orbit interactions and time-reversal symmetry. Researchers are chasing efficient […]

Recovering native chemical information from surface-enhanced Raman scattering

Recovering native chemical information from surface-enhanced Raman scattering

ChemistryCondensed matterPhysicsQuantum physics

By DIPC

For centuries, metals were employed in optical applications only as mirrors and gratings. New vistas opened up in the late 1970s and early 1980s with the discovery of surface-enhanced Raman scattering and the use of surface plasmon (collective electronic oscillations at the surface of metals) resonances for sensing. However, it was not until the 1990s […]

The tautomerization of porphycene on Cu(111) in simple physical terms

The tautomerization of porphycene on Cu(111) in simple physical terms

Condensed matterQuantum physicsTheoretical physics

By DIPC

There are compounds, called isomers, that have the same molecular formulae but different molecular structures or different arrangements of atoms in space. In the so-called cis-trans isomerism, isomers have different positions of groups or specific atoms with respect to a double bond, a ring or a central atom. For example, the numbers in the name […]

A link between straintronics and valleytronics in graphene

A link between straintronics and valleytronics in graphene

Condensed matterMaterialsNanotechnologyQuantum physicsTheoretical physics

By DIPC

So-called “valleytronics” is a new type of electronics that could lead to faster and more efficient computer logic systems and data storage chips in next-generation devices. Valley electrons are so named because they carry a valley “degree of freedom.” This is a new way to harness electrons for information processing that’s in addition to utilizing […]