Quantum technology is seen as an important future-oriented technology: smaller, faster and with higher performance than conventional electronics. However, exploiting quantum effects is difficult because nature’s smallest building blocks have properties quite distinct from those we know from our everyday world. An international team of researchers has now succeeded in extracting a fault tolerant manipulation of quanta from an effect of classical mechanics.
The motion of a tennis racket in the air can help predict the behavior of quanta. “Using an analogy from classical physics aids us in more efficiently designing and illustrating control elements for phenomena in the quantum world,” reports Stefan Glaser, professor in the Department of Chemistry at the Technical University of Munich (TUM).
“Controlling the properties of quanta and using them in technical processes has proven difficult thus far because the quanta adhere to their own laws, which often exceed our imagination,” explains the scientist. “Possible applications such as secure networks, highly sensitive measuring equipment and ultrafast quantum computers are thus still in their infancy.”
Quanta under control
“Utilizing quantum effects in a technical manner by influencing the behavior of particles through electromagnetic fields required the fastest possible methods to develop fault-tolerant control sequences,” says Glaser. “To date, most of the methods build on very complicated computational processes.”
Together with an international team of physicists, chemists and mathematicians, the researcher has now discovered an unexpected, promising and novel approach: Using the tennis racket effect, a well-known phenomenon in classical mechanics, the consistent alteration in the spin of quanta via electromagnetic control commands can be visualized.
Tennis racket in motion
The tennis racket effect describes what happens when one tosses a tennis racket into the air while imparting a rotation about an axis. When one spins the racket about its transverse axis a surprising effect appears: In addition to the intended 360-degree rotation about its transverse axis, the racket will almost always perform an unexpected 180-degree flip about its longitudinal axis. When the racket is caught, the initial bottom side will be facing up.
“Responsible for this effect are tiny deviations and perturbations during the toss and the different moments of inertia along the three axes of an asymmetrical body. The effect can also be observed by tossing a book or cell phone into the air – for good measure over a soft bedding – instead of a tennis racket,” elucidates Glaser. The longest and shortest axes are stable. However, the intermediate axis, in the case of a tennis racket, the transverse axis, is unstable and even miniscule agitations reliably trigger an additional 180-degree rotation.
Quanta in motion
Quanta also possess angular momentum, known as spin. This can be influenced by applying an electromagnetic field. “The aim of this quantum technique is to change the orientation of the spin in a targeted manner, thereby minimizing errors caused by small perturbations,” says Glaser.
“The discovered mathematical analogy between the geometric properties of classical physics pertaining to freely rotating objects and controlling quantum phenomena can now be utilized to optimize the electromagnetic control of quantum states,” summarizes co-author Prof. Dominique Sugny. The scientist works at the French University of Burgundy, as well as a Hans Fischer Fellow at the Institute for Advanced Study at TUM.
New, robust models
Using measurements of the nuclear spin, the team could demonstrate experimentally that the tennis racket effect really does improve the robustness of scattering sequences. They have now published their results in the journal “Scientific Reports.”
“Based on these research results, we can now develop more efficient mathematical models that allow errors to be avoided when controlling quantum processors,” adds Glaser. “Building on the well-understood phenomenon from classical physics, we can not only visualize the development of reliable control sequences in quantum technology, but also accelerate them significantly.”
The research was funded by the German Research Foundation (DFG), the French National Research Agency (ANR) and the French National Center of Scientific Research (CNRS), the Mexican funding program Convocatorias Abiertas Fondo de Cooperación Internacional en Ciencia y Tecnología del Conacyt (FONCICYT), the Autonomous National University of Mexico, the Bavarian Elite Network and the Technical University of Munich via the Institute for Advanced Study funded by the German Excellence Initiative and the European Union. The experiments were conducted at the Bavarian NMR Center in Garching.
Breaking Newton’s law
Visualization of the matrix
Prof. Dr. Steffen Glaser
Technical University of Munich
Chair of Organic Chemistry
Lichtenbergstr.4, 85748 Garching, Germany
Tel.: +49 89 289 52602 – E-Mail: email@example.com – Web: http://www.ocnmr.ch.tum.de/
Prof. Dr. Dominique Sugny
Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB)
UMR 5209 CNRS-Université Bourgogne Franche Comté
9 Av. A. Savary, BP 47 870, F-21078, Dijon Cedex, France
Tel.: +33 380 395972 – E-Mail: Dominique.Sugny@u-bourgogne.fr
https://www.tum.de/en/about-tum/news/press-releases/detail/article/34054/ Link to the Press release
Dr. Ulrich Marsch | Technische Universität München
What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin
Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
19.07.2018 | Earth Sciences
19.07.2018 | Power and Electrical Engineering
19.07.2018 | Materials Sciences