Exotic quantum states: A new research approach

Oct 03, 2011
Majorana fermions are then generated at both ends of the atomic chain. Graphic: H. Ritsch

(PhysOrg.com) -- Theoretical physicists of the University of Innsbruck have formulated a new concept to engineer exotic, so-called topological states of matter in quantum mechanical many-body systems. They linked concepts of quantum optics and condensed matter physics and show a direction to build a quantum computer which is immune against perturbations. The scientists have published their work in the journal Nature Physics.

Three years ago a research team led by Sebastian Diehl and Peter Zoller presented a completely new approach to engineer quantum states in many-body systems. They used a physical phenomenon that normally increases the degree of disorder in a system dramatically: dissipation. In classical physics dissipation is the concept that explains the production of heat through friction. Surprisingly, in dissipation can also lead to order and a completely pure many-body state can be realized. This spring an Innsbruck research team, led by experimental physicist Rainer Blatt, demonstrated experimentally that by using dissipation certain can be generated and intensified. By linking concepts of quantum optics and , theoretical physicists from the Institute of Theoretical Physics of the University of Innsbruck and the Institute for and Quantum Information of the Austrian Academy of Sciences have now pointed out a new direction of how dissipation may be used in another beneficial and promising way.

In condensed matter physics a new concept to describe order in many-body systems has gained in importance recently: topological order. Two examples for topological phenomena are the , which was demonstrated in the 1980s, and the topological insulator, which behaves as an in its interior while permitting the transport of charges on its surface. Sebastian Diehl and Peter Zoller’s team of now suggest realizing dissipation induced Majorana fermions in a quantum system. This topological phenomenon was named after the Italian physicist Ettore Majorana and describes particles that are their own anti-particles. “We show a new way of how Majorana fermions may be created in a controlled way in a quantum system,“ explains Sebastian Diehl. “For this purpose we use a dissipative dynamic that drives the system into this state in a targeted way and compels it back when affected by disturbances.” With this new approach Diehl and his team combine the advantages of dissipation and topological order - both concepts are highly robust against perturbations such as disorder. Therefore, their suggestion to create Majorana fermions in an atomic quantum wire is of high interest for experimental implementation. It may be used for building a quantum computer whose basic building blocks consist of Majorana fermions. In quantum wires atoms are confined to one-dimensional structures by optical lattices which are generated by laser beams: Majorana fermions are then generated at both ends of the atomic chain.

START awardee Sebastian Diehl and his research group have linked the knowledge of condensed matter physics and quantum mechanics. “We work at the interface between those two disciplines, which creates exciting new possibilities,“ says Diehl. First though, they had to prove beyond all doubt that the concept of topological order can be transferred to a dissipative context at all. “We were able to tick off all points on the topological checklist and show that its prerequisites are also valid in a system with dissipative dynamics.” The physicists have published the mathematical proof of this new approach in the journal Nature Physics.

Explore further: The importance of three-way atom interactions in maintaining coherence

More information: Topology by Dissipation in Atomic Quantum Wires. S. Diehl, E. Rico, M. A. Baranov, P. Zoller. Nature Physics. 2. Oktober 2011 DOI: 10.1038/nphys2106

Provided by University of Innsbruck

4.7 /5 (3 votes)
add to favorites email to friend print save as pdf

Related Stories

Pinning atoms into order

Jul 28, 2010

In an international first, physicists of the University of Innsbruck, Austria have experimentally observed a quantum phenomenon, where an arbitrarily weak perturbation causes atoms to build an organized structure ...

Recommended for you

Finding faster-than-light particles by weighing them

Dec 26, 2014

In a new paper accepted by the journal Astroparticle Physics, Robert Ehrlich, a recently retired physicist from George Mason University, claims that the neutrino is very likely a tachyon or faster-than-light par ...

Controlling core switching in Pac-man disks

Dec 24, 2014

Magnetic vortices in thin films can encode information in the perpendicular magnetization pointing up or down relative to the vortex core. These binary states could be useful for non-volatile data storage ...

World's most complex crystal simulated

Dec 24, 2014

The most complicated crystal structure ever produced in a computer simulation has been achieved by researchers at the University of Michigan. They say the findings help demonstrate how complexity can emerge ...

Atoms queue up for quantum computer networks

Dec 24, 2014

In order to develop future quantum computer networks, it is necessary to hold a known number of atoms and read them without them disappearing. To do this, researchers from the Niels Bohr Institute have developed ...

New video supports radiation dosimetry audits

Dec 23, 2014

The National Physical Laboratory (NPL), working with the National Radiotherapy Trials Quality Assurance Group, has produced a video guideĀ to support physicists participating in radiation dosimetry audits.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.