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Archive for the ‘quantum physics’ category: Page 398

Apr 10, 2020

Fine-tuning magnetic spin for faster, smaller memory devices

Posted by in categories: computing, quantum physics

Unlike the magnetic materials used to make a typical memory device, antiferromagnets won’t stick to your fridge. That’s because the magnetic spins in antiferromagnets are oppositely aligned and cancel each other out.

Scientists have long theorized that antiferromagnets have potential as materials for ultrafast stable memories. But no one could figure out how to manipulate their magnetization to read and write information in a device.

Now, a team of researchers at Berkeley Lab and UC Berkeley working in the Center for Novel Pathways to Quantum Coherence in Materials, an Energy Frontier Research Center funded by the U.S. Department of Energy, have developed an antiferromagnetic switch for computer memory and processing applications. Their findings, published in the journal Nature Materials, have implications for further miniaturizing computing devices and personal electronics without loss of performance.

Apr 9, 2020

Seeqc raises $5M to help make quantum computing commercially viable

Posted by in categories: computing, finance, quantum physics

Seeqc, a startup that is part of a relatively new class of quantum computing companies that is looking at how to best use classical computing to manage quantum processors, today announced that it has raised $5 million from M Ventures, the strategic corporate venture capital arm of Merck, the German pharmaceutical giant. Merck will be a strategic partner for Seeqc and will help it to develop its R&D efforts to develop useful application-specific quantum computers.

With this, New York state-based Seeqc has now raised a total of $11 million, including a recent $6.8 million seed round that included BlueYard Capital, Cambium, NewLab and the Partnership Fund for New York City.

Since developing new pharmaceuticals is an obvious use case for quantum computing, it makes sense that large pharmaceutical companies are trying to get ahead of their competitors by making strategic investments in companies like Seeqc.

Apr 9, 2020

Collisional cooling of ultracold molecules

Posted by in categories: chemistry, particle physics, quantum physics

Since the original work on Bose–Einstein condensation1,2, the use of quantum degenerate gases of atoms has enabled the quantum emulation of important systems in condensed matter and nuclear physics, as well as the study of many-body states that have no analogue in other fields of physics3. Ultracold molecules in the micro- and nanokelvin regimes are expected to bring powerful capabilities to quantum emulation4 and quantum computing5, owing to their rich internal degrees of freedom compared to atoms, and to facilitate precision measurement and the study of quantum chemistry6. Quantum gases of ultracold atoms can be created using collision-based cooling schemes such as evaporative cooling, but thermalization and collisional cooling have not yet been realized for ultracold molecules. Other techniques, such as the use of supersonic jets and cryogenic buffer gases, have reached temperatures limited to above 10 millikelvin7,8. Here we show cooling of NaLi molecules to micro- and nanokelvin temperatures through collisions with ultracold Na atoms, with both molecules and atoms prepared in their stretched hyperfine spin states. We find a lower bound on the ratio of elastic to inelastic molecule–atom collisions that is greater than 50—large enough to support sustained collisional cooling. By employing two stages of evaporation, we increase the phase-space density of the molecules by a factor of 20, achieving temperatures as low as 220 nanokelvin. The favourable collisional properties of the Na–NaLi system could enable the creation of deeply quantum degenerate dipolar molecules and raises the possibility of using stretched spin states in the cooling of other molecules.

Apr 8, 2020

First successful laser trapping of circular Rydberg atoms

Posted by in categories: particle physics, quantum physics

Rydberg atoms, which are atoms in a highly excited state, have several unique and advantageous properties, including a particularly long lifetime and large sensitivities to external fields. These properties make them valuable for a variety of applications, for instance for the development of quantum technologies.

In order for Rydberg atoms to be effectively used in quantum technology, however, researchers first need to be able to trap them. While a number of studies have demonstrated the trapping of Rydberg atoms using magnetic, electric, or , the trapping times achieved so far have been relatively short, typically around 100μs.

Researchers at Laboratoire Kastler Brossel (LKB) have recently achieved a longer 2-D laser trapping time of circular Rydberg atoms of up to 10 ms. The method they employed, outlined in a paper published in Physical Review Letters, could open up exciting new possibilities for the development of .

Apr 8, 2020

A physicist explains what CBS show The Big Bang Theory gets right with ‘super asymmetry’

Posted by in categories: cosmology, quantum physics

Adilson Motter, Northwestern University

After 12 successful seasons, “The Big Bang Theory” has finally come to a fulfilling end, concluding its reign as the longest running multicamera sitcom on TV.

If you’re one of the few who haven’t seen the show, this CBS series centers around a group of young scientists defined by essentially every possible stereotype about nerds and geeks. The main character, Sheldon (Jim Parsons), is a theoretical physicist. He is exceptionally intelligent, but also socially unconventional, egocentric, envious and ultra-competitive. His best friend, Leonard (Johnny Galecki), is an experimental physicist who, although more balanced, also shows more fluency with quantum physics than with ordinary social situations.

Apr 8, 2020

New ‘refrigerator’ super-cools molecules to nanokelvin temperatures

Posted by in categories: computing, particle physics, quantum physics

For years, scientists have looked for ways to cool molecules down to ultracold temperatures, at which point the molecules should slow to a crawl, allowing scientists to precisely control their quantum behavior. This could enable researchers to use molecules as complex bits for quantum computing, tuning individual molecules like tiny knobs to carry out multiple streams of calculations at a time.

While scientists have super-cooled atoms, doing the same for , which are more complex in their behavior and structure, has proven to be a much bigger challenge.

Now MIT physicists have found a way to cool molecules of lithium down to 200 billionths of a Kelvin, just a hair above absolute zero. They did so by applying a technique called collisional cooling, in which they immersed molecules of cold sodium lithium in a cloud of even colder sodium atoms. The acted as a refrigerant to cool the molecules even further.

Apr 8, 2020

New “refrigerator” super-cools molecules to nanokelvin temperatures

Posted by in categories: computing, particle physics, quantum physics

“Collisional cooling has been the workhorse for cooling atoms,” adds Nobel Prize laureate Wolfgang Ketterle, the John D. Arthur professor of physics at MIT. “I wasn’t convinced that our scheme would work, but since we didn’t know for sure, we had to try it. We know now that it works for cooling sodium lithium molecules. Whether it will work for other classes of molecules remains to be seen.” MIT School of Science, Harvard — MIT Center for Ultracold Atoms, RLE at MIT — Research Laboratory of Electronics at MIT, #research #supercooledatoms #nanokelvin #WolfgangKetterle


Technique may enable molecule-based quantum computing.

Apr 8, 2020

From Quantum Optics to Quantum Technologies

Posted by in categories: computing, quantum physics

Abstract: Quantum optics is the study of the intrinsically quantum properties of light. During the second part of the 20th century experimental and theoretical progress developed together; nowadays quantum optics provides a testbed of many fundamental aspects of quantum mechanics such as coherence and quantum entanglement. Quantum optics helped trigger, both directly and indirectly, the birth of quantum technologies, whose aim is to harness non-classical quantum effects in applications from quantum key distribution to quantum computing. Quantum light remains at the heart of many of the most promising and potentially transformative quantum technologies. In this review, we celebrate the work of Sir Peter Knight and present an overview of the development of quantum optics and its impact on quantum technologies research. We describe the core theoretical tools developed to express and study the quantum properties of light, the key experimental approaches used to control, manipulate and measure such properties and their application in quantum simulation, and quantum computing.

Apr 7, 2020

This Breakthrough Just Got Us One Step Closer to a Quantum Internet

Posted by in categories: internet, military, quantum physics, satellites

The US is well behind China on this front, though. A team led by quantum supremo Jian-Wei Pan have already demonstrated a host of breakthroughs in transmitting quantum signals to satellites, most recently developing a mobile quantum satellite station.

The reason both countries are rushing to develop the technology is that it could provide an ultra-secure communication channel in an era where cyberwarfare is becoming increasingly common.

I t’s essentially impossible to eavesdrop on a quantum conversation. The strange rules of quantum mechanics mean that measuring a quantum state immediately changes it, so any message encoded in quantum states will be corrupted if someone tries to intercept it.

Apr 7, 2020

Investors Pour $215 Million Into Quantum Computer Promising 1 Million Qubits – Enough Processing Power to Reshape Nearly Every Industry

Posted by in categories: computing, quantum physics

A new quantum computer under development is slated to have 1 million qubits – significantly more powerful than Google’s most recent milestone. PsiQuantum Corp., a Silicon Valley company, is developing a photon-based commercial quantum computer that runs on light. The company has raised $215 million from investors with participation from BlackRock Advisors, Founders Fund, Atomico and Redpoint Ventures. The company’s ote.

While a working prototype is estimated to be years away, the advanced technology is aiming to blow away the competition with a far superior machine.

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