Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: quantum physics – Page 665

Micro-combs — optical frequency combs generated by integrated micro-cavity resonators – offer the full potential of their bulk counterparts, but in an integrated footprint. They have enabled breakthroughs in many fields including spectroscopy, microwave photonics, frequency synthesis, optical ranging, quantum sources, metrology and ultrahigh capacity data transmission. Here, by using a powerful class of micro-comb called soliton crystals, we achieve ultra-high data transmission over 75 km of standard optical fibre using a single integrated chip source. We demonstrate a line rate of 44.2 Terabits s−1 using the telecommunications C-band at 1550 nm with a spectral efficiency of 10.4 bits s−1 Hz−1. Soliton crystals exhibit robust and stable generation and operation as well as a high intrinsic efficiency that, together with an extremely low soliton micro-comb spacing of 48.9 GHz enable the use of a very high coherent data modulation format (64 QAM — quadrature amplitude modulated). This work demonstrates the capability of optical micro-combs to perform in demanding and practical optical communications networks.

Read more | >

Education Saturday with Space Time.

This episode of space time is brought to you by the information flowing through an impossibly complex network of quantum entanglement, that just happens to mutually agree that you and I exist inside it. Oh, and Schrodinger’s cat is in here too.

In quantum world things are routinely in multiple states at once – what we call a “superposition” of states. But in the classical world of large scales, things are either this or that. The famous thought experiment is Schrodinger’s cat – in which a cat is in an opaque box with a vial of deadly poison that’s released on the radioactive decay of an atom. Quantum mechanics tells us that the atom’sfunction can be in a superposition of states – simultaneously decayed or not decayed. So is the cat’sfunction also in a superposition of both dead and alive.

Read more | >

If you’re interested in superlongevity and superintelligence, then I have a book to recommend., by Sonia Contera, is a book about the intersection of biotech and nanotech. Interesting and well written for the layman, the book covers some of the latest developments in nanotechnology as it applies to biological matters. Although there are many topics, I was primarily interested in the DNA nanobots, DNA origami, and the protein nanotechnology sections. My interest is piqued in these arenas due to my expectation that DNA nanobots and protein nanobots, as well as complex self-assembled custom nanostructures, are going to be key to some of the longevity technologies and some of the possible substrates for mind uploading that are key to superlongevity and superintelligence. There are also sections in the book on 3D bioprinted organs — progress and possibilities, as well as difficulties.

There is even a section that clearly was written specifically to address a discussion that has engaged my friends, Dinorah Delfin and Dan Faggella. The title is:

FUTURE DEVICES: QUANTUM PHYSICS MEETS BIOLOGY MEETS NANOTECHNOLOGY

Now, some might be tempted to consider that particular combination to be “woo woo”, however, please keep in mind the author’s credentials. Sonia Contera is a professor of biological physics in the Department of Physics at the University of Oxford.

Increasingly, scientists are gaining control over matter at the nanometer scale. Spearheaded by physical scientists operating at the interfaces of physics and biology, advances in nanoscience and technology are transforming how people think about life and treat human health.

Read more | >

Magnesium dimer (Mg2) is a fragile molecule consisting of two weakly interacting atoms held together by the laws of quantum mechanics. It has recently emerged as a potential probe for understanding fundamental phenomena at the intersection of chemistry and ultracold physics, but its use has been thwarted by a half-century-old enigma—five high-lying vibrational states that hold the key to understanding how the magnesium atoms interact but have eluded detection for 50 years.

The lowest fourteen Mg2 vibrational states were discovered in the 1970s, but both early and recent experiments should have observed a total of nineteen states. Like a quantum cold case, experimental efforts to find the last five failed, and Mg2 was almost forgotten. Until now.

Piotr Piecuch, Michigan State University Distinguished Professor and MSU Foundation Professor of chemistry, along with College of Natural Science Department of Chemistry graduate students Stephen H. Yuwono and Ilias Magoulas, developed new, computationally derived evidence that not only made a in first-principles quantum chemistry, but finally solved the 50-year-old Mg2 mystery.

Read more | >

Researchers at the Swiss Federal Institute of Technology Lausanne (EPFL) and IBM Research Europe recently demonstrated the laser cooling of a nanomechanical oscillator down to its zero-point energy (i.e., the point at which it contains a minimum amount of energy). Their successful demonstration, featured in Physical Review Letters, could have important implications for the development quantum technologies.

Read more | >

Molecular dynamics is at the point of simulating bulk matter – but don’t expect it to predict the future.

The TV series Devs took as its premise the idea that a quantum computer of sufficient power could simulate the world so completely that it could project events accurately back into the distant past (the Crucifixion or prehistory) and predict the future. At face value somewhat absurd, the scenario supplied a framework on which to hang questions about determinism and free will (and less happily, the Many Worlds interpretation of quantum mechanics).

Quite what quantum computers will do for molecular simulations remains to be seen, but the excitement about them shouldn’t eclipse the staggering advances still being made in classical simulation. Full ab initio quantum-chemical calculations are very computationally expensive even with the inevitable approximations they entail, so it has been challenging to bring this degree of precision to traditional molecular dynamics, where molecular interactions are still typically described by classical potentials. Even simulating pure water, where accurate modelling of hydrogen bonding and the ionic disassociation of molecules involves quantum effects, has been tough.

Read more | >

Fault-tolerant logic gates will consume a large proportion of the resources of a two-dimensional quantum computing architecture. Here we show how to perform a fault-tolerant non-Clifford gate with the surface code; a quantum error-correcting code now under intensive development. This alleviates the need for distillation or higher-dimensional components to complete a universal gate set. The operation uses both local transversal gates and code deformations over a time that scales with the size of the qubit array. An important component of the gate is a just-in-time decoder. These decoding algorithms allow us to draw upon the advantages of three-dimensional models using only a two-dimensional array of live qubits. Our gate is completed using parity checks of weight no greater than four. We therefore expect it to be amenable with near-future technology. As the gate circumvents the need for magic-state distillation, it may reduce the resource overhead of surface-code quantum computation considerably.

A scalable quantum computer is expected to solve difficult problems that are intractable with classical technology. Scaling such a machine to a useful size will necessarily require fault-tolerant components that protect quantum information as the data is processed (1–4). If we are to see the realization of a quantum computer, its design must respect the constraints of the quantum architecture that can be prepared in the laboratory. In many cases, for instance, superconducting qubits (5–7), this restricts us to two-dimensional architectures.

Leading candidate models for fault-tolerant quantum computation are based on the surface code (3, 8) due to its high threshold (9) and multitude of ways of performing Clifford gates (10). Universal quantum computation is possible if this gate set is supplemented by a non-Clifford gate. Among the most feasible approaches to realize a non-Clifford gate is by the use of magic-state distillation (11). However, this is somewhat prohibitive as a large fraction of the resources of a quantum computer will be expended by these protocols (12, 13).

Read more | >

Microsoft today announced that Azure Quantum, its partner-centric quantum computing platform for developers who want to get started with quantum computing, is now in limited preview. First announced at Microsoft Ignite 2019, Azure Quantum brings together the hardware from IonQ, Honeywell, QCI and Microsoft, services from the likes of 1QBit, and the classical computing capabilities of the Azure cloud. With this move to being in limited preview, Microsoft is now opening the service up to a small number of select partners and customers.

At its current stage, quantum computing isn’t exactly a mission-critical capability for any business, but given how fast things are moving and how powerful the technology will be once it’s matured a bit over the next few years, many experts argue that now is the time to get started — especially because of how different quantum computing is from classical computing and how it will take developers a while to develop.

Read more | >