Archive for the ‘computing’ category: Page 10

Sep 15, 2021

New Chip Can Decode Any Type of Data Sent Across a Network

Posted by in categories: computing, information science, internet, virtual reality

Every piece of data that travels over the internet — from paragraphs in an email to 3D graphics in a virtual reality environment — can be altered by the noise it encounters along the way, such as electromagnetic interference from a microwave or Bluetooth device. The data are coded so that when they arrive at their destination, a decoding algorithm can undo the negative effects of that noise and retrieve the original data.

Since the 1950s, most error-correcting codes and decoding algorithms have been designed together. Each code had a structure that corresponded with a particular, highly complex decoding algorithm, which often required the use of dedicated hardware.

Researchers at MIT.

Sep 14, 2021

Otherworldly ‘time crystal’ made inside Google quantum computer could change physics forever

Posted by in categories: computing, quantum physics

The crystals neatly sidestep some of physics’ most iron-clad laws.

Sep 13, 2021

Time-magnified photon counting with 550-fs resolution

Posted by in categories: computing, nanotechnology, quantum physics

Time-resolved photon counting plays an indispensable role in precision metrology in both classical and quantum regimes. Therein, time-correlated single-photon counting (TCSPC) [1] has been the key enabling technology for applications such as fluorescence lifetime microscopy [2], time-gated Raman spectroscopy [3], photon counting time-of-flight (ToF) 3D imaging [4], light-in-flight imaging [5], and computational diffuse optical tomography [6]. For all these applications, one of the most important figures of merit is the single-photon timing resolution (SPTR, also referred to as photon counting timing jitter). The TCSPC SPTR is limited by the available single-photon detectors. For example, photomultiplier tubes typically provide an SPTR larger than 100 ps [7]. Meanwhile, superconducting nanowire single-photon detectors have superior SPTR in the sub-10-ps range [8, 9]. However, cryogenic cooling significantly increases the system complexity. Single-photon avalanche diodes (SPADs) operate at moderate temperature, which makes them a popular choice for various applications mentioned above. Nevertheless, their SPTR is still limited to tens-of-picoseconds level [10]. On the other hand, orders-of-magnitude enhancement on SPTR is required for many challenging applications such as the study of ultrafast fluorescent decay dynamics [11,12].

In this Letter, we demonstrate a time-magnified TCSPC (TM-TCSPC) that achieves an ultrashort SPTR of 550 fs using an off-the-shelf single-photon detector. The key component is a quantum temporal magnifier using a low-noise high-efficiency fiber parametric time lens [13,14] based on four-wave mixing Bragg scattering (FWM-BS) [15 17]. A temporal magnification of 130 with a 97% photon conversion efficiency has been achieved while maintaining the quantum coherence of the signal under test (SUT). Detection sensitivity of -{95}\;rm{dBm}$ (0.03 photons per pulse), limited by the spontaneous Raman scattering noise, is possible and allows efficient processing and characterization of quantum-level SUT. The TM-TCSPC can resolve ultrashort pulses with a 130-fs pulse width difference at a 22-fs accuracy. When applied to photon counting ToF 3D imaging, the TM-TCSPC greatly suppresses the range walk error (RWE) that limits all photon counting ToF 3D imaging systems by 99.2% (130 times) and thus provides high depth measurement accuracy and precision of 26 µm and 3 µm, respectively. The TM-TCSPC is a promising solution for photon counting at the femtosecond regime that will benefit various research fields such as fluorescence lifetime microscopy, time-gated Raman spectroscopy, light-in-flight imaging, and computational diffuse optical tomography.

Sep 12, 2021

Atomically-Thin, Twisted Graphene Has Unique Properties That Could Advance Quantum Computing

Posted by in categories: computing, quantum physics

Researchers describe how electrons move through two-dimensional layered graphene 0 findings that could lead to advances in the design of future quantum computing platforms.

New research published in Physical Review Letters describes how electrons move through two different configurations of bilayer graphene, the atomically-thin form of carbon. This study, the result of a collaboration between Brookhaven National Laboratory, the University of Pennsylvania, the University of New Hampshire, Stony Brook University, and Columbia University 0 provides insights that researchers could use to design more powerful and secure quantum computing platforms in the future.

“Today’s computer chips are based on our knowledge of how electrons move in semiconductors, specifically silicon,” says first and co-corresponding author Zhongwei Dai, a postdoc at Brookhaven. “But the physical properties of silicon are reaching a physical limit in terms of how small transistors can be made and how many can fit on a chip. If we can understand how electrons move at the small scale of a few nanometers in the reduced dimensions of 2-D materials, we may be able to unlock another way to utilize electrons for quantum information science.”

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Sep 11, 2021

Largest virtual universe free for anyone to explore

Posted by in categories: alien life, computing, particle physics

Forget about online games that promise you a “whole world” to explore. An international team of researchers has generated an entire virtual universe, and made it freely available on the cloud to everyone.

Uchuu (meaning “outer space” in Japanese) is the largest and most realistic simulation of the to date. The Uchuu simulation consists of 2.1 trillion particles in a computational cube an unprecedented 9.63 billion light-years to a side. For comparison, that’s about three-quarters the distance between Earth and the most distant observed . Uchuu reveals the evolution of the universe on a level of both size and detail inconceivable until now.

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Sep 11, 2021

TSMC Price Hikes to Result in Higher Retail Pricing For Pretty Much Everything

Posted by in categories: computing, mobile phones

Chip shortage should last until mid-2023.

Low-end smartphones and PCs to get more expensive because of chip prices.

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Sep 10, 2021

How Horizon Plans To Bring Quantum Computing Out Of The Shadows

Posted by in categories: business, computing, quantum physics

New tools are required if businesses are to take advantage of quantum computing, argues Horizon’s Joe Fitzsimons.

Sep 10, 2021

A Laser Fired Through a Keyhole Can Expose Everything Inside a Room

Posted by in category: computing

The keyhole imaging technique, developed by researchers at Stanford University’s Computational Imaging Lab, is so named because all that’s needed to see what’s inside a closed room is a tiny hole (such as a keyhole or a peephole) large enough to shine a laser beam through, creating a single dot of light on a wall inside.

If you’re worried about privacy, it might be time to cover up your front door’s peephole.

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Sep 9, 2021

‘Excitons’ Show Potential for Low-Power Quantum Computing

Posted by in categories: computing, quantum physics

Circa 2019

LONDON — A laboratory in Switzerland has found a way of using a laser to change and regulate the polarization, wavelength and intensity of light in “excitons” in 2D materials, creating the potential for a new generation of transistors with less energy loss and heat dissipation, opening up the potential for low-power quantum computing.

Excitons are created when an electron absorbs light and moves into a higher energy level, or “energy band” as it is called in solid quantum physics. This excited electron leaves behind an “electron hole” in its previous energy band. And because the electron has a negative charge and the hole a positive charge, the two are bound together by an electrostatic force called a Coulomb force. It’s this electron-electron hole pair that is referred to as an exciton.

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Sep 9, 2021

Solving Quantum Ground-State Problems with Nuclear Magnetic Resonance

Posted by in categories: chemistry, computing, information science, quantum physics

Circa 2012

Quantum ground-state problems are computationally hard problems for general many-body Hamiltonians; there is no classical or quantum algorithm known to be able to solve them efficiently. Nevertheless, if a trial wavefunction approximating the ground state is available, as often happens for many problems in physics and chemistry, a quantum computer could employ this trial wavefunction to project the ground state by means of the phase estimation algorithm (PEA). We performed an experimental realization of this idea by implementing a variational-wavefunction approach to solve the ground-state problem of the Heisenberg spin model with an NMR quantum simulator. Our iterative phase estimation procedure yields a high accuracy for the eigenenergies (to the 10–5 decimal digit).

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