QT/ Evading the uncertainty principle in quantum physics
Tags: Quantum Physics, Quantum Computing, Science, Physics

TL;DR

In quantum mechanics, the Heisenberg uncertainty principle dictates that the position and speed of an object cannot both be known fully precisely at the same time. Researchers now show that two vibrating drumheads, the size of a human hair, can be prepared in a quantum state which evades the uncertainty principle.

Researchers have big ideas for the potential of quantum technology, from unhackable networks to earthquake sensors. But all these things depend on a major technological feat: being able to build and control systems of quantum particles, which are among the smallest objects in the universe. That goal is now a step closer with the publication of a new method by University of Chicago scientists. Published in Nature, the paper shows how to bring multiple molecules at once into a single quantum state — one of the most important goals in quantum physics.

Quantum systems consisting of several particles can be used to measure magnetic or electric fields more precisely. A young physicist at the University of Basel has now proposed a new scheme for such measurements that uses a particular kind of correlation between quantum particles.

Scientists characterized how the electronic states in a compound containing iron, tellurium, and selenium depend on local chemical concentrations. They discovered that superconductivity (conducting electricity without resistance), along with distinct magnetic correlations, appears when the local concentration of iron is sufficiently low; a coexisting electronic state existing only at the surface (topological surface state) arises when the concentration of tellurium is sufficiently high. Reported in Nature Materials, their findings point to the composition range necessary for topological superconductivity. Topological superconductivity could enable more robust quantum computing, which promises to deliver exponential increases in processing power.

Researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory, the University of Chicago and scientific institutes and universities in Japan, Korea and Hungary have established guidelines that will be an invaluable resource for the discovery of new defect-based quantum systems.

Scientists from the University of Bristol’s Quantum Engineering Technology Labs (QETLabs) have developed an algorithm that provides valuable insights into the physics underlying quantum systems — paving the way for significant advances in quantum computation and sensing, and potentially turning a new page in scientific investigation.

The ability to turn on and off a physical process with just one photon is a fundamental building block for quantum photonic technologies. Realizing this in a chip-scale architecture is important for scalability, which amplifies a breakthrough by City College of New York researchers led by physicist Vinod Menon. They’ve demonstrated for the first time the use of “Rydberg states” in solid state materials (previously shown in cold atom gases) to enhance nonlinear optical interactions to unprecedented levels in solid state systems. This feat is a first step towards realizing chip-scale scalable single photon switches.

Researchers have developed a method that allows for simulation and visualization of magnetic-field-induced electron currents inside gold nanoparticles. The method facilitates accurate analysis of magnetic field effects inside complex nanostructures in nuclear magnetic resonance measurements and establishes quantitative criteria for aromaticity of nanoparticles.

The future of particle acceleration has begun. Awake is a promising concept for a completely new method with which particles can be accelerated even over short distances. The basis for this is a plasma wave that accelerates electrons and thus brings them to high energies. A team led by the Max Planck Institute for Physics now reports a breakthrough in this context. For the first time, they were able to precisely time the production of the proton microbunches that drive the wave in the plasma. This fulfills an important prerequisite for using the Awake technology for collision experiments.

And more!

Quantum Computing Market

According to the recent market research report ‘Quantum Computing Market with COVID-19 impact by Offering (Systems and Services), Deployment (On Premises and Cloud Based), Application, Technology, End-use Industry and Region — Global Forecast to 2026’, published by MarketsandMarkets, the Quantum Computing market is expected to grow from USD 472 million in 2021 to USD 1,765 million by 2026, at a CAGR of 30.2%. The early adoption of quantum computing in the banking and finance sector is expected to fuel the growth of the market globally. Other key factors contributing to the growth of the quantum computing market include rising investments by governments of different countries to carry out research and development activities related to quantum computing technology. Several companies are focusing on the adoption of QCaaS post-COVID-19. This, in turn, is expected to contribute to the growth of the quantum computing market. However, stability and error correction issues are expected to restrain the growth of the market.

According to ‘Quantum Computing Market Research Report: By Offering, Deployment Type, Application, Technology, Industry — Industry Share, Growth, Drivers, Trends and Demand Forecast to 2030’ report, the quantum computing market is projected to reach $64,988 million by 2030. Machine learning (ML) is expected to progress at the highest CAGR, during the forecast period, among all application categories, owing to the fact that quantum computing is being integrated in ML for improving the latter’s use case.

By 2030, Europe and North America are expected to account for more than 78.0% in the quantum computing market, as Canada, the U.S., the U.K., Germany, and Russia are witnessing heavy investments in the field.

Latest Researches

by Laure Mercier de Lépinay, Caspar F. Ockeloen-Korppi, Matthew J. Woolley, Mika A. Sillanpää in Science

The uncertainty principle, first introduced by Werner Heisenberg in the late 1920’s, is a fundamental concept of quantum mechanics. In the quantum world, particles like the electrons that power all electrical product can also behave like waves. As a result, particles cannot have a well-defined position and momentum simultaneously. For instance, measuring the momentum of a particle leads to a disturbance of position, and therefore the position cannot be precisely defined.

In recent research, published in Science, a team led by Prof. Mika Sillanpää at Aalto University in Finland has shown that there is a way to get around the uncertainty principle. The team included Dr. Matt Woolley from the University of New South Wales in Australia, who developed the theoretical model for the experiment.

Instead of elementary particles, the team carried out the experiments using much larger objects: two vibrating drumheads one-fifth of the width of a human hair. The drumheads were carefully coerced into behaving quantum mechanically.

“In our work, the drumheads exhibit a collective quantum motion. The drums vibrate in an opposite phase to each other, such that when one of them is in an end position of the vibration cycle, the other is in the opposite position at the same time. In this situation, the quantum uncertainty of the drums’ motion is cancelled if the two drums are treated as one quantum-mechanical entity,” explains the lead author of the study, Dr. Laure Mercier de Lepinay.

This means that the researchers were able to simultaneously measure the position and the momentum of the two drumheads — which should not be possible according to the Heisenberg uncertainty principle. Breaking the rule allows them to be able to characterize extremely weak forces driving the drumheads.

“One of the drums responds to all the forces of the other drum in the opposing way, kind of with a negative mass,” Sillanpää says.

Furthermore, the researchers also exploited this result to provide the most solid evidence to date that such large objects can exhibit what is known as quantum entanglement. Entangled objects cannot be described independently of each other, even though they may have an arbitrarily large spatial separation. Entanglement allows pairs of objects to behave in ways that contradict classical physics, and is the key resource behind emerging quantum technologies. A quantum computer can, for example, carry out the types of calculations needed to invent new medicines much faster than any supercomputer ever could.

In macroscopic objects, quantum effects like entanglement are very fragile, and are destroyed easily by any disturbances from their surrounding environment. Therefore, the experiments were carried out at a very low temperature, only a hundredth a degree above absolute zero at -273 degrees.

In the future, the research group will use these ideas in laboratory tests aiming at probing the interplay of quantum mechanics and gravity. The vibrating drumheads may also serve as interfaces for connecting nodes of large-scale, distributed quantum networks.