## Archive for the ‘quantum physics’ category

We only ever experience three spatial dimensions, but quantum lab experiments suggest a whole new side to reality – weird particle apparitions included.

Normally an insulator, diamond becomes a metallic conductor when subjected to large strain in a new theoretical model.

Long known as the hardest of all natural materials, diamonds are also exceptional thermal conductors and electrical insulators. Now, researchers have discovered a way to tweak tiny needles of diamond in a controlled way to transform their electronic properties, dialing them from insulating, through semiconducting, all the way to highly conductive, or metallic. This can be induced dynamically and reversed at will, with no degradation of the diamond material.

The research, though still at an early proof-of-concept stage, may open up a wide array of potential applications, including new kinds of broadband solar cells, highly efficient LEDs and power electronics, and new optical devices or quantum sensors, the researchers say.

Learn how you can benefit from quantum computing and solve currently unsolvable questions. Here are some resources available to start your journey.

I t’s an exciting time to be in q uantu m information science. I nv estments are growing across the globe, like the recent ly announced U.S. Quantum Information Science Research Centers, that bring together the best of the public and private sectors to solve the scientific challenges on the path to a commercial-scale quantum computer. While there’ s increased research investment worldwide, there are not yet enough skilled developers, engineers, and researchers to take advantage of this emerging quantum revolution.

Here’s where you come in. There ’s no better time to start learning about how you can benefit from quantum computing, a nd solve currently unsolvable questions in the future. Here are some of the resour ces available to start your journey.

Have you ever been in more than one place at the same time? If you’re much bigger than an atom, the answer will be no.

But atoms and particles are governed by the rules of quantum mechanics, in which several different possible situations can coexist at once.

Light is incredible. You can bend it, you can bounce it, and researchers have now found a way to trap light, physically move it, and then release it again.

This incredible feat of physics was demonstrated at the Johannes Gutenberg University Mainz and published in Physics Review Letters. Researchers trapped light in a quantum memory, a cloud of ultra-cold rubidium atoms. The quantum memory was then moved 1.2 millimeters and the light was released with little impact on its properties.

“We stored the light by putting it in a suitcase so to speak, only that in our case the suitcase was made of a cloud of cold atoms. We moved this suitcase over a short distance and then took the light out again. This is very interesting not only for physics in general, but also for quantum communication because light is not very easy to ‘capture’, and if you want to transport it elsewhere in a controlled manner, it usually ends up being lost,” senior author Professor Patrick Windpassinger said in a statement.

In this episode, we’re tackling the question that’s on everyone’s minds: what will it take to have quantum internet in our home?
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A quantum internet is in the works.

Freeze laser.

We demonstrate ground-state cooling of a trapped ion using radio-frequency (rf) radiation. This is a powerful tool for the implementation of quantum operations, where rf or microwave radiation instead of lasers is used for motional quantum state engineering. We measure a mean phonon number of $\overline{n}=0.13$ after sideband cooling, corresponding to a ground-state occupation probability of 88%. After preparing in the vibrational ground state, we demonstrate motional state engineering by driving Rabi oscillations between the $|n=0⟩$ and $|n=1⟩$ Fock states. We also use the ability to ground-state cool to accurately measure the motional heating rate and report a reduction by almost 2 orders of magnitude compared with our previously measured result, which we attribute to carefully eliminating sources of electrical noise in the system.

A collaboration between researchers from The University of Western Australia and The University of California Merced has provided a new way to measure tiny forces and use them to control objects.

The research, published recently in Nature Physics, was jointly led by Professor Michael Tobar, from UWA’s School of Physics, Mathematics and Computing and Chief Investigator at the Australian Research Council Centre of Excellence for Engineered Quantum Systems and Dr. Jacob Pate from the University of Merced.

Professor Tobar said that the result allowed a new way to manipulate and control macroscopic objects in a non-contacting way, allowing enhanced sensitivity without adding loss.

A team of physicists led by Professor Patrick Windpassinger at Johannes Gutenberg University Mainz (JGU) has successfully transported light stored in a quantum memory over a distance of 1.2 millimeters. They have demonstrated that the controlled transport process and its dynamics has only little impact on the properties of the stored light. The researchers used ultra-cold rubidium-87 atoms as a storage medium for the light as to achieve a high level of storage efficiency and a long lifetime.

“We stored the light by putting it in a suitcase so to speak, only that in our case the suitcase was made of a cloud of cold atoms. We moved this suitcase over a short distance and then took the light out again. This is very interesting not only for physics in general, but also for , because light is not very easy to ‘capture’, and if you want to transport it elsewhere in a controlled manner, it usually ends up being lost,” said Professor Patrick Windpassinger, explaining the complicated process.

The controlled manipulation and storage of quantum information as well as the ability to retrieve it are essential prerequisites for achieving advances in quantum communication and for performing corresponding computer operations in the quantum world. Optical quantum memories, which allow for the storage and on-demand retrieval of quantum information carried by light, are essential for scalable quantum communication networks. For instance, they can represent important building blocks of quantum repeaters or tools in linear quantum computing. In recent years, ensembles of atoms have proven to be media well suited for storing and retrieving optical quantum information. Using a technique known as electromagnetically induced transparency (EIT), incident light pulses can be trapped and coherently mapped to create a collective excitation of the atoms. Since the process is largely reversible, the light can then be retrieved again with high efficiency.

The Higgs mode associated with the amplitude fluctuation of an order parameter can decay into other low-energy bosonic modes, which renders the Higgs mode usually unstable in condensed matter systems. Here, the authors propose a mechanism to stabilize the Higgs mode in anisotropic quantum magnets. They show that magnetic anisotropy gaps out the Goldstone magnon mode and stabilizes the Higgs mode near a quantum critical point. The results are supported by three independent approaches: a bond-operator method, field theory, and quantum Monte Carlo simulation with analytic continuation.

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