Decay is relentless in the macroscopic world: broken objects do not fit themselves back together again. However, other laws are valid in the quantum world: new research shows that so-called quasiparticles can decay and reorganize themselves again and are thus become virtually immortal. These are good prospects for the development of durable data memories.
As the saying goes, nothing lasts forever. The laws of physics confirm this: on our planet, all processes increase entropy, thus molecular disorder. For example, a broken glass would never put itself back together again.
Theoretical physicists at the Technical University of Munich (TUM) and the Max Planck Institute for the Physics of Complex Systems have discovered that things which seem inconceivable in the everyday world are possible on a microscopic level.
“Until now, the assumption was that quasiparticles in interacting quantum systems decay after a certain time. We now know that the opposite is the case: strong interactions can even stop decay entirely,” explains Frank Pollmann, Professor for Theoretical Solid-State Physics at the TUM. Collective lattice vibrations in crystals, so-called phonons, are one example of such quasiparticles.
The concept of quasiparticles was coined by the physicist and Nobel prize winner Lev Davidovich Landau. He used it to describe collective states of lots of particles or rather their interactions due to electrical or magnetic forces. Due to this interaction, several particles act like one single one.
Numeric methods open up new perspectives
Up until now, it wasn’t known in detail which processes influence the fate of these quasiparticles in interacting systems,” says Pollmann. “It is only now that we possess numerical methods with which we can calculate complex interactions as well as computers with a performance which is high enough to solve these equations.”
“The result of the elaborate simulation: admittedly, quasiparticles do decay, however new, identical particle entities emerge from the debris,” says the lead author, Ruben Verresen. “If this decay proceeds very quickly, an inverse reaction will occur after a certain time and the debris will converge again. This process can recur endlessly and a sustained oscillation between decay and rebirth emerges.”
From a physical point of view, this oscillation is a wave which is transformed into matter, which, according to quantum mechanical wave-particle duality, is possible. Therefore, the immortal quasiparticles do not transgress the second law of thermodynamics. Their entropy remains constant, decay has been stopped.
The reality check
The discovery also explains phenomena which were baffling until now. Experimental physicists had measured that the magnetic compound Ba3CoSB2O9 is astonishingly stable. Magnetic quasiparticles, magnons, are responsible for it. Other quasiparticles, rotons, ensure that helium which is a gas on the earth’s surface becomes a liquid at absolute zero which can flow unrestricted.
“Our work is purely basic research,“ emphasizes Pollmann. However, it is perfectly possible that one day the results will even allow for applications, for example the construction of durable data memories for future quantum computers.
The research work was funded by the European Research Council (ERC) and the German Research Foundation (DFG) within the framework of the [Collaborative Research Center] SFB 1143, the Research Unit FOR1807 as well as the cluster of excellence Nanosystems Initiative Munich (NIM). Work will be carried on in the cluster of excellence Munich Center for Quantum Science and Technology (MCQST).
Prof. Dr. Frank Pollmann
Professorship for Theoretical and Solid State Physics
Tel.: +49 89 289 53760
Ruben Verresen, Roderich Moessner & Frank Pollmann
Avoided quasiparticle decay from strong quantum interactions
nature physics, May 27, 2019
Dr. Ulrich Marsch | Technische Universität München
Simple experiment explains magnetic resonance
09.12.2019 | University of California - Riverside
Electronic map reveals 'rules of the road' in superconductor
09.12.2019 | Rice University
Using a clever technique that causes unruly crystals of iron selenide to snap into alignment, Rice University physicists have drawn a detailed map that reveals...
University of Texas and MIT researchers create virtual UAVs that can predict vehicle health, enable autonomous decision-making
In the not too distant future, we can expect to see our skies filled with unmanned aerial vehicles (UAVs) delivering packages, maybe even people, from location...
With ultracold chemistry, researchers get a first look at exactly what happens during a chemical reaction
The coldest chemical reaction in the known universe took place in what appears to be a chaotic mess of lasers. The appearance deceives: Deep within that...
Abnormal scarring is a serious threat resulting in non-healing chronic wounds or fibrosis. Scars form when fibroblasts, a type of cell of connective tissue, reach wounded skin and deposit plugs of extracellular matrix. Until today, the question about the exact anatomical origin of these fibroblasts has not been answered. In order to find potential ways of influencing the scarring process, the team of Dr. Yuval Rinkevich, Group Leader for Regenerative Biology at the Institute of Lung Biology and Disease at Helmholtz Zentrum München, aimed to finally find an answer. As it was already known that all scars derive from a fibroblast lineage expressing the Engrailed-1 gene - a lineage not only present in skin, but also in fascia - the researchers intentionally tried to understand whether or not fascia might be the origin of fibroblasts.
Fibroblasts kit - ready to heal wounds
Research from a leading international expert on the health of the Great Lakes suggests that the growing intensity and scale of pollution from plastics poses serious risks to human health and will continue to have profound consequences on the ecosystem.
In an article published this month in the Journal of Waste Resources and Recycling, Gail Krantzberg, a professor in the Booth School of Engineering Practice...
03.12.2019 | Event News
15.11.2019 | Event News
15.11.2019 | Event News
09.12.2019 | Earth Sciences
09.12.2019 | Information Technology
09.12.2019 | Life Sciences