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Primeur weekly 2019-05-13

Exascale supercomputing

AMD EPYC CPUs, AMD Radeon Instinct GPUs and ROCm Open Source software to power world's fastest supercomputer at Oak Ridge National Laboratory ...

U.S. Department of Energy and Cray to deliver record-setting Frontier supercomputer at ORNL ...

Cray pursues advanced research with DOE for exascale systems ...

CAAR accepting application team proposals for Frontier system ...

Quantum computing

Computing faster with quasi-particles ...

Quantum computing with graphene plasmons ...

Focus on Europe

ELIXIR and GA4GH expand collaboration ...

Netherlands eScience Center labeled "Center of Excellence" by international review committee ...

HPC stakeholders in Europe get together at EuroHPC Summit Week 2019 ...

Middleware

DDN announces intent to acquire Nexenta, a market expert in Software-Defined Storage for 5G and IoT ...

Hardware

Austria's Central Institution for Meteorology and Geodynamics improves weather nowcasting with Cray AI solutions ...

Cray reports first quarter 2019 financial results ...

CoolIT Systems announces liquid cooling solution for Intel Server System S9200WK ...

Hewlett Packard Enterprise integrates BlueData to accelerate Artificial Intelligence and data-driven innovation in the enterprise ...

Intel previews design innovation: 10nm CPU ships in June and 7nm product in 2021 ...

WekaIO Matrix selected by Mellanox Technologies to accelerate EDA workloads ...

Applications

King's College London and NVIDIA build UK's first AI platform for NHS hospitals ...

Quantum sensor for photons ...

Comet-enabled simulations showcase black holes and their magnetic bubbles ...

Ultra-secure form of virtual money proposed ...

Shaping the future of finance with HPC ...

NCSA scientist employs supercomputer simulations in Ohio gerrymandering case ...

Superfacility framework advances photosynthesis research ...

The Cloud

Supermicro introduces open private Cloud solutions based on new Red Hat Enterprise Linux 8 ...

NetApp powers data-driven organisations to succeed ...

Computing faster with quasi-particles


Scheme of a two-dimensional Josephson junction: A normal conducting two-dimensional electron gas sandwiched between two superconductors S (grey). If an in-plane magnetic field is applied, Majorana fermions are expected to appear at the ends of the normal region. Credit: Picture: Ewelina Hankiewicz.
10 May 2019 Würzburg - Majorana particles are very peculiar members of the family of elementary particles. First predicted in 1937 by the Italian physicist Ettore Majorana, these particles belong to the group of so-called fermions, a group that also includes electrons, neutrons and protons. Majorana fermions are electrically neutral and also their own anti-particles. These exotic particles can, for example, emerge as quasi-particles in topological superconductors and represent ideal building blocks for topological quantum computers.

On the road to such topological quantum computers based on Majorana quasi-particles, physicists from the University of Würzburg together with colleagues from Harvard University (USA) have made an important step: Whereas previous experiments in this field have mostly focused on one-dimensional systems, the teams from Würzburg and Harvard have succeeded in going to two-dimensional systems.

In this collaboration, the groups of Ewelina Hankiewicz, Theoretische Physik IV, and Laurens Molenkamp, Experimentelle Physik III, from the University of Würzburg teamed up with the groups of Amir Yacoby and Bertrand Halperin from Harvard University. Their findings are presented in the current issue of the scientific journal Nature .

"Realizing Majorana fermions is one of the most intensely studied topics in condensed matter physics", Ewelina Hankiewicz stated. According to her, previous realizations have usually focused on one-dimensional systems such as nanowires. She explains that a manipulation of Majorana fermions is very difficult in these setups. It would therefore require significant efforts to make Majorana fermions in these setups eventually applicable for quantum computing.

In order to avoid some of these difficulties, the researchers have studied Majorana fermions in a two-dimensional system with strong spin-orbit coupling. "The system we investigate is a so-called phase-controlled Josephson junction, that is, two superconductors that are separated by a normal region", Laurens Molenkamp explained. The superconducting phase difference between the two superconductors provides an additional knob, which makes an intricate fine-tuning of the other system parameters at least partially unnecessary.

In the material studied, a mercury telluride quantum well coupled to superconducting thin-film aluminium, the physicists observed for the first time a topological phase transition which implies the appearance of Majorana fermions in phase-controlled Josephson junctions. The set-up realized experimentally here constitutes a versatile platform for the creation, manipulation and control of Majorana fermions, which offers several advantages compared to previous one-dimensional platforms. According to Ewelina Hankiewicz, "this is an important step towards an improved control of Majorana fermions". The proof of concept of a topological superconductor based on a two-dimensional Josephson junction opens up new possibilities for the research on Majorana fermions in condensed matter physics. In particular, several constraints of previous realizations of Majorana fermions can be avoided.

At the same time, an improved control of Majorana fermions represents an important step towards topological quantum computers. Theoretically, such computers can be significantly more powerful than conventional computers. They thus have the potential to revolutionize computer technology.

Next, the researchers plan to improve the Josephson junctions and move towards junctions with narrower normal regions. Here, more localized Majorana fermions are expected. They further study additional possibilities of manipulating Majorana fermions, for example, by using other semiconductors.

Source: University of Würzburg

Back to Table of contents

Primeur weekly 2019-05-13

Exascale supercomputing

AMD EPYC CPUs, AMD Radeon Instinct GPUs and ROCm Open Source software to power world's fastest supercomputer at Oak Ridge National Laboratory ...

U.S. Department of Energy and Cray to deliver record-setting Frontier supercomputer at ORNL ...

Cray pursues advanced research with DOE for exascale systems ...

CAAR accepting application team proposals for Frontier system ...

Quantum computing

Computing faster with quasi-particles ...

Quantum computing with graphene plasmons ...

Focus on Europe

ELIXIR and GA4GH expand collaboration ...

Netherlands eScience Center labeled "Center of Excellence" by international review committee ...

HPC stakeholders in Europe get together at EuroHPC Summit Week 2019 ...

Middleware

DDN announces intent to acquire Nexenta, a market expert in Software-Defined Storage for 5G and IoT ...

Hardware

Austria's Central Institution for Meteorology and Geodynamics improves weather nowcasting with Cray AI solutions ...

Cray reports first quarter 2019 financial results ...

CoolIT Systems announces liquid cooling solution for Intel Server System S9200WK ...

Hewlett Packard Enterprise integrates BlueData to accelerate Artificial Intelligence and data-driven innovation in the enterprise ...

Intel previews design innovation: 10nm CPU ships in June and 7nm product in 2021 ...

WekaIO Matrix selected by Mellanox Technologies to accelerate EDA workloads ...

Applications

King's College London and NVIDIA build UK's first AI platform for NHS hospitals ...

Quantum sensor for photons ...

Comet-enabled simulations showcase black holes and their magnetic bubbles ...

Ultra-secure form of virtual money proposed ...

Shaping the future of finance with HPC ...

NCSA scientist employs supercomputer simulations in Ohio gerrymandering case ...

Superfacility framework advances photosynthesis research ...

The Cloud

Supermicro introduces open private Cloud solutions based on new Red Hat Enterprise Linux 8 ...

NetApp powers data-driven organisations to succeed ...