https://www.youtube.com/watch?v=HvJGsF4t2Tc
The king is dead, long live the king… of supercomputers!
In this video I discuss New Fastest Supercomputer in the World and the first official Exascale supercomputer — Frontier Supercomputer located at Oak Ridge Lab.
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As physicists dig deeper into the quantum realm, they are discovering an infinitesimally small world composed of a strange and surprising array of links, knots, and winding. Some quantum materials exhibit magnetic whirls called skyrmions — unique configurations sometimes described as “subatomic hurricanes.” Others host a form of superconductivity that twists into vortices.
Now, in an article published in the journal Nature, a Princeton-led team of scientists has discovered that electrons in quantum matter can link one another in strange new ways. The work brings together ideas in three areas of science – condensed matter physics, topology, and knot theory – in a new way, raising unexpected questions about the quantum properties of electronic systems.
Topology is the branch of theoretical mathematics that studies geometric properties that can be deformed but not intrinsically changed. Topological quantum states first came to the public’s attention in 2016 when three scientists, including Duncan Haldane, who is Princeton’s Thomas D. Jones Professor of Mathematical Physics and Sherman Fairchild University Professor of Physics, were awarded the Nobel Prize for their theoretical prediction of topology in electronic materials.
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The experiment will investigate the Unruh effect, which is produced by a mixture of quantum mechanics and special relativity.
A completely new kind of molecule has been made by combining an extremely cold ion and a super-sized atom. The unusual molecular bond between the two particles was thousands of times longer than those in most room-temperature molecules, and the method to make and study it could kick-start a new branch of ultracold quantum chemistry.
For instance, continuous-variable (CV) QKD has its own distinct advantages at a metropolitan distance36,37 due to the use of common components of coherent optical communication technology. In addition, the homodyne38 or heterodyne39 measurements used by CV-QKD have inherent extraordinary spectral filtering capabilities, which allows the crosstalk in wavelength division multiplexing (WDM) channels to be effectively suppressed. Therefore, hundreds of QKD channels may be integrated into a single optical fiber and can be cotransmitted with classic data channels. This allows QKD channels to be more effectively integrated into existing communication networks. In CV-QKD, discrete modulation technology has attracted much attention31,40,41,42,43,44,45,46,47,48,49,50 because of its ability to reduce the requirements for modulation devices. However, due to the lack of symmetry, the security proof of discrete modulation CV-QKD also mainly relies on numerical methods43,44,45,46,47,48,51.
Unfortunately, calculating a secure key rate by numerical methods requires minimizing a convex function over all eavesdropping attacks related with the experimental data52,53. The efficiency of this optimization depends on the number of parameters of the QKD protocol. For example, in discrete modulation CV-QKD, the number of parameters is generally \(1000–3000\) depending on the different choices of cutoff photon numbers44. This leads to the corresponding optimization possibly taking minutes or even hours51. Therefore, it is especially important to develop tools for calculating the key rate that are more efficient than numerical methods.
In this work, we take the homodyne detection discrete-modulated CV-QKD44 as an example to construct a neural network capable of predicting the secure key rate for the purpose of saving time and resource consumption. We apply our neural network to a test set obtained at different excess noises and distances. Excellent accuracy and time savings are observed after adjusting the hyperparameters. Importantly, the predicted key rates are highly likely to be secure. Note that our method is versatile and can be extended to quickly calculate the complex secure key rates of various other unstructured quantum key distribution protocols. Through some open source deep learning frameworks for on-device inference, such as TensorFlow Lite54, our model can also be easily deployed on devices at the edge of the network, such as mobile devices, embedded Linux or microcontrollers.
The famous double-slit experiment–a now classic showcase of how both light and matter are able to behave as both waves, and particles in their “classical” physical definition–seems almost like magic to many of us.
Because of this unusual function of our physical universe, the double-slit experiment has intrigued physicists for decades, as it suggests the possibility of multiple universes or weird quantum events. However, only recently have researchers at the Vienna University of Technology (TU Wien) found a way to fully validate this experiment, using a particular measurement method on the particle.
Can quantum science supercharge genetics? | Jim Al-Khalili for Big Think.
This interview is an episode from The Well, our new publication about ideas that inspire a life well-lived, created with the John Templeton Foundation.
Continue reading “What if quantum physics could eradicate illness? | Jim Al-Khalili for Big Think” »
Researchers in Delft have succeeded in teleporting quantum information across a rudimentary network. This first of its kind is an important step towards a future quantum internet. This breakthrough was made possible by a greatly improved quantum memory and enhanced quality of the quantum links between the three nodes of the network. The researchers, working at QuTech—a collaboration between Delft University of Technology and the Netherlands Organization for Applied Scientific Research (TNO)—are publishing their findings today in the scientific journal Nature.
The power of a future quantum internet is based on the ability to send quantum information (quantum bits) between the nodes of the network. This will enable all kinds of applications such as securely sharing confidential information, linking several quantum computers together to increase their computing capability, and the use of highly precise, linked quantum sensors.
In modern computers, errors during processing and storage of information have become a rarity due to high-quality fabrication. However, for critical applications, where even single errors can have serious effects, error correction mechanisms based on redundancy of the processed data are still used.
Quantum computers are inherently much more susceptible to disturbances and will thus probably always require error correction mechanisms, because otherwise errors will propagate uncontrolled in the system and information will be lost. Because the fundamental laws of quantum mechanics forbid copying quantum information, redundancy can be achieved by distributing logical quantum information into an entangled state of several physical systems, for example multiple individual atoms.
The team led by Thomas Monz of the Department of Experimental Physics at the University of Innsbruck and Markus Müller of RWTH Aachen University and Forschungszentrum Jülich in Germany has now succeeded for the first time in realizing a set of computational operations on two logical quantum bits that can be used to implement any possible operation. “For a real-world quantum computer, we need a universal set of gates with which we can program all algorithms,” explains Lukas Postler, an experimental physicist from Innsbruck.
Scientists realize quantum teleportation between remote, non-neighboring nodes in a quantum network. The network employs three optically connected nodes based on solid-state spin qubits. The teleporter is prepared by establishing remote entanglement on the two links, followed by entanglement swapping on the middle node and storage in a memory qubit.
They demonstrate that once successful preparation of the teleporter is heralded, arbitrary qubit states can be teleported with fidelity above the classical bound, even with unit efficiency. These results are enabled by key innovations in the qubit readout procedure, active memory qubit protection during entanglement generation and tailored heralding that reduces remote entanglement infidelities.
