• June 2020
    M T W T F S S

Scientists Succeed in Measuring Electron Spin Qubit Without Demolishing It RIKEN

March 3, 2020

Scientists at the RIKEN Center for Emergent Matter Science in Japan have successfully measured electron spin in a silicon quantum dot (QD) without altering its spin. Such measurements have been difficult, as spin typically is impacted by the process of reading out single electron spins in silicon, which is to convert the spins into charges for fast detection. The researchers used the Ising model to transfer spin data of an electron in a QD to an electron in a neighboring QD; they then were able to measure the neighbor’s spin while leaving the original electron untouched. Using this method, said RIKEN’s Seigo Tarucha, yielded a non-demolition fidelity rate of 99%, a readout accuracy of 95%, and a theoretical accuracy upgrade to 99.6%.


The Case of the Elusive Majorana: So-Called ‘Angel Particle’ Still a Mystery Penn State News

Sam Sholtis
January 3, 2020

A study by researchers at Pennsylvania (Penn) State University and Germany’s University of Wurzburg casts doubt on the reported discovery of the chiral Majorana fermion in 2017. Analog versions of Majorana fermions are considered a potential pathway for building a topological quantum computer, with quantum bits shielded from environmental decoherence. The researchers analyzed dozens of devices similar to the one used to generate the so-called angel particle in the 2017 report. They found that the feature claimed to be the manifestation of the Majorana fermion was unlikely to be triggered by its existence. Said Penn State’s Cui-Zu Chang, “An important first step toward this distant dream of creating a topological quantum computer is to demonstrate definitive experimental evidence for the existence of Majorana fermions in condensed matter. Over the past seven or so years, several experiments have claimed to show such evidence, but the interpretation of these experiments is still debated.”


Intel’s Jim Clarke on its New Cryo-controller and why Intel isn’t Late to the Quantum Party

By John Russell

December 9, 2019

Intel today introduced the ‘first-of-its-kind’ cryo-controller chip for quantum computing and previewed a cryo-prober tool for characterizing quantum processor chips. The new controller is a mixed-signal SoC named Horse Ridge after one of the coldest regions in Oregon and is designed to operate at approximately 4 Kelvin.


Google Plans to Demonstrate the Supremacy of Quantum Computing

IEEE Spectrum, Rachel Courtland
May 24, 2017

Google researchers say they plan to boost the volume of superconducting qubits built on integrated circuits (ICs) to create a 7×7 array and push operations to the limits of even the best supercomputers, demonstrating “quantum supremacy” by year’s end. The team says it will perform operations on a 49-qubit system that will trigger chaotic evolution yielding what appears to be random output, which classical computers can model for smaller systems. University of California, Santa Barbara professor John Martinis says the qubits constituting the array also could be employed to build larger “universal” quantum systems with error correction, capable of performing useful tasks such as decryption. Martinis says the challenge of scaling up the quantum IC involves maintaining qubits’ function without losing fidelity or boosting error rates. “Error rate and scaling tend to kind of compete against each other,” he notes. The team also sees the possibility of scaling up systems beyond 50 qubits without error correction.



Google Moves Closer to a Universal Quantum Computer

Nature (06/08/16) Philip Ball

A research team has made an experimental prototype of a universal quantum computer that can solve a wide range of problems in fields such as chemistry and physics, and has the potential to be scaled up to larger systems. The Google prototype combines the best of analog and digital approaches to quantum computing. Google computer scientists and physicists at the University of California, Santa Barbara (UC Santa Barbara) and the University of the Basque Country in Bilbao, Spain, used a row of nine solid-state quantum bits (qubits) fashioned from cross-shaped films of aluminum about 400 micrometers from tip to tip, deposited them onto a sapphire surface, and cooled the metal to turn it into a superconductor with no electrical resistance. Information could be encoded into the qubits in their superconducting state, and interactions between neighboring qubits were controlled by logic gates that steer the qubits digitally into a state that encodes the solution to a problem. The researchers say their approach should enable a computer with quantum error correction, and they predict devices with more than 40 qubits could be a reality in a couple of years. “At that point, it will become possible to simulate quantum dynamics that is inaccessible on classical hardware, which will mark the advent of ‘quantum supremacy,'” says UC Santa Barbara’s Daniel Lidar.


Reducing Big Data Using Ideas From Quantum Theory Makes It Easier to Interpret

Queen Mary, University of London (04/23/15) Will Hoyles

Researchers from Queen Mary University of London (QMUL) and Rovira i Virgili University have developed a new method that simplifies the way big data is represented and processed. Borrowing ideas from quantum theory, the team implemented techniques used to understand the difference between two quantum states. The researchers applied the quantum mechanical method to several large publicly available data sets, and were better able to understand which relationships in a system are similar enough to be considered redundant. The researchers say their method can significantly reduce the amount of information that has to be displayed and analyzed separately and make it easier to understand. Moreover, the approach reduces the computing power needed to process large amounts of multidimensional relational data. “We’ve been trying to find ways of simplifying the way big data is represented and processed and we were inspired by the way that the complex relationships in quantum theory are understood,” says QMUL’s Vincenzo Nicosia. “With so much data being gathered by companies and governments nowadays, we hope this method will make it easier to analyze and make sense of it, as well as reducing computing costs by cutting down the amount of processing required to extract useful information.”


The Race Towards Quantum Computation

CORDIS News (11/27/14)

At the recent Innovation Summit, European quantum computing experts touted the European Union’s (EU) achievements in the field and called for further EU investments in quantum computing research and development. The Delft University of Technology’s Lieven Vandersypen predicted future Nobel Prizes would be awarded to Europeans for achievements in quantum computing research. Vandersypen and University College London’s John Morton said quantum computing will unlock tremendous potential for developing new medicines and complex materials, new diagnostic tools, and energy technologies. However, both said the EU is in danger of falling behind other nations. Morton noted the EU leads all other regions in terms of academic output regarding quantum technologies, but is falling behind in patenting quantum technologies; for example, China patented five times more quantum technologies than the EU between 2009 and 2012. Morton suggested the EU create an advisory board for quantum technology with at least 50-percent representation from the information technology industry to help guide the development and commercialization of quantum technologies. Vandersypen called for a “large-scale EU-wide effort” similar in scale to the Human Brain Project, which is pushing forward brain science.