Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

Home > Press > Scientists tame Josephson vortices

Experimental setup. The blue and orange indicate niobium and copper, respectively. The ellipse marks the area of ??the Josephson junction. The cobalt-chromium-coated tip oscillates, excited by a piezo element (dither). The optic fiber is used to read out the oscillations

CREDIT
Viacheslav Dremov et al./Nature Communications
Experimental setup. The blue and orange indicate niobium and copper, respectively. The ellipse marks the area of ??the Josephson junction. The cobalt-chromium-coated tip oscillates, excited by a piezo element (dither). The optic fiber is used to read out the oscillations CREDIT Viacheslav Dremov et al./Nature Communications

Abstract:
MIPT physicists have learned how to locally control Josephson vortices. The discovery can be used for quantum electronics superconducting devices and future quantum processors. The work has been published in the prestigious scientific journal Nature Communications.

Scientists tame Josephson vortices

Moscow, Russia | Posted on November 1st, 2019

A Josephson vortex is a vortex of currents occurring in a system of two superconductors separated by a weak link -- a dielectric, a normal metal, etc. -- in the presence of an external magnetic field. In 1962, Brian Josephson predicted the flow of a supercurrent through a thin layer of insulating material separating two pieces of superconducting material. This current was named the Josephson current, and the coupling of superconductors was dubbed a Josephson junction. A so-called weak link occurs between the two superconductors through a dielectric or a nonsuperconducting metal, and macroscopic quantum coherence develops.

When this system is placed in a magnetic field, the superconductors push the magnetic field out. The greater the magnetic field applied, the more the superconductivity resists the magnetic field penetrating into the Josephson system. However, the weak link is a place in which the field can penetrate in the form of individual Josephson vortices carrying magnetic flux quanta. Josephson vortices are often seen as real topological objects, 2 pi-phase singularities that are hard to observe and manipulate.

Researchers from the MIPT Laboratory of Topological Quantum Phenomena in Superconducting Systems applied a magnetic force microscope to study Josephson vortices in a system of two superconducting niobium contacts interlaid with a copper layer acting as a weak link.

"We have demonstrated that in the planar (flat) superconductor-normal metal-superconductor contacts, Josephson vortices have a unique imprint," said the paper's senior author, Vasily Stolyarov of MIPT. "We found this by observing these structures with a magnetic force microscope. Based on this discovery, we demonstrated the possibility of locally generating Josephson vortices, which can be manipulated by the magnetic cantilever of a microscope. Our research is yet another step toward creating future superconducting quantum computing machines."

The variety of ultrasensitive superconducting devices, qubits, and architectures for quantum computing is growing rapidly. It is expected that superconducting quantum electronic devices will challenge conventional semiconductor devices very soon. These new devices will rely on Josephson junctions like the one indicated by the yellow closed arrow in figure 1.

"It is quite difficult to visualize Josephson vortices, as they are poorly localized," Stolyarov added. "We discovered a way to measure the dissipation that occurs during the creation and destruction of such a vortex in the weak link area. Dissipation is a minor release of energy. In our case, the energy is released when a vortex moves in a planar Josephson contact. Thus, using our magnetic force microscope, we can successfully detect not only the static magnetic portrait of the superconducting structure but also the dynamic processes in it."

The authors of the paper demonstrated a method for remote generation, detection, and manipulation of Josephson vortices in planar Josephson junctions using a low-temperature magnetic force microscope. With certain parameters (probe location, temperature, external magnetic field, electric current flow through the sample), the team observed a particular response of the microscope cantilever. This was followed by the appearance of sharp rings/arcs in the images. The researchers identified these features as bifurcation points between adjacent Josephson states characterized by a different number or position of Josephson vortices inside the junction. The process is accompanied by the exchange of energy between the cantilever and the sample at the bifurcation points and demonstrates that a magnetic force microscope can provide unique information on the state of a Josephson vortex.

It is expected that the results of the research will serve as an impetus and a basis for developing new methods of local noncontact diagnostics and management of modern superconducting devices and superconducting quantum electronics.

###

The study was supported by the Russian Science Foundation and the Ministry of Education and Science of the Russian Federation.

####

For more information, please click here

Contacts:
Varvara Bogomolova

7-916-147-4496

@phystech_en

Copyright © Moscow Institute of Physics and Technology

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

RELATED JOURNAL ARTICLE:

Related News Press

News and information

Let the europium shine brighter January 21st, 2020

Nanotubes may give the world better batteries: Rice U. scientists' method quenches lithium metal dendrites in batteries that charge faster, last longer January 16th, 2020

Quantum physics: Controlled experiment observes self-organized criticality January 16th, 2020

Quantum Physics

Study finds billions of quantum entangled electrons in 'strange metal' Physicists provide direct evidence of entanglement's role in quantum criticality January 16th, 2020

Quantum physics: Controlled experiment observes self-organized criticality January 16th, 2020

ORNL researchers advance performance benchmark for quantum computers January 3rd, 2020

A quantum breakthrough brings a technique from astronomy to the nano-scale: Multi-messenger approach allows scientists to probe electronic and magnetic materials at ultra-small length scales January 3rd, 2020

Quantum engine operating at maximum power: A new experimental proof-of-concept quantum Otto cycle, using nuclear spins, has reached an efficiency close to its thermodynamic limit at maximum power December 20th, 2019

Magnetism

Generation and Manipulation of spin currents for advanced electronic devices January 9th, 2020

Govt.-Legislation/Regulation/Funding/Policy

Study finds billions of quantum entangled electrons in 'strange metal' Physicists provide direct evidence of entanglement's role in quantum criticality January 16th, 2020

Pretty with a twist: Complex porous, chiral nano-patterns arise from a simple linear building block January 16th, 2020

Toward safer disposal of printed circuit boards January 16th, 2020

Researchers gain control over internal structure of self-assembled composite materials January 16th, 2020

Possible Futures

Let the europium shine brighter January 21st, 2020

Study finds billions of quantum entangled electrons in 'strange metal' Physicists provide direct evidence of entanglement's role in quantum criticality January 16th, 2020

Nanotubes may give the world better batteries: Rice U. scientists' method quenches lithium metal dendrites in batteries that charge faster, last longer January 16th, 2020

Researchers gain control over internal structure of self-assembled composite materials January 16th, 2020

Chip Technology

Toward safer disposal of printed circuit boards January 16th, 2020

Generation and Manipulation of spin currents for advanced electronic devices January 9th, 2020

NUS scientists create world’s first monolayer amorphous film January 9th, 2020

Onto Innovation to Present at the 22nd Annual Needham Growth Conference January 3rd, 2020

Quantum Computing

ORNL researchers advance performance benchmark for quantum computers January 3rd, 2020

In leap for quantum computing, silicon quantum bits establish a long-distance relationship: Princeton scientists demonstrate that two silicon quantum bits can communicate across relatively long distances in a turning point for the technology December 27th, 2019

A distinct spin on atomic transport: Work that demonstrates simultaneous control over transport and spin properties of cold atoms establishes a framework for exploring concepts of spintronics and solid-state physics November 8th, 2019

Thorium superconductivity: Scientists discover a new high-temperature superconductor November 8th, 2019

Discoveries

Let the europium shine brighter January 21st, 2020

Quantum physics: Controlled experiment observes self-organized criticality January 16th, 2020

Pretty with a twist: Complex porous, chiral nano-patterns arise from a simple linear building block January 16th, 2020

Toward safer disposal of printed circuit boards January 16th, 2020

Announcements

Let the europium shine brighter January 21st, 2020

Quantum physics: Controlled experiment observes self-organized criticality January 16th, 2020

Pretty with a twist: Complex porous, chiral nano-patterns arise from a simple linear building block January 16th, 2020

Toward safer disposal of printed circuit boards January 16th, 2020

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters

Let the europium shine brighter January 21st, 2020

Quantum physics: Controlled experiment observes self-organized criticality January 16th, 2020

Pretty with a twist: Complex porous, chiral nano-patterns arise from a simple linear building block January 16th, 2020

Toward safer disposal of printed circuit boards January 16th, 2020

Quantum nanoscience

A quantum breakthrough brings a technique from astronomy to the nano-scale: Multi-messenger approach allows scientists to probe electronic and magnetic materials at ultra-small length scales January 3rd, 2020

Quantum engine operating at maximum power: A new experimental proof-of-concept quantum Otto cycle, using nuclear spins, has reached an efficiency close to its thermodynamic limit at maximum power December 20th, 2019

New laser technique images quantum world in a trillionth of a second: Technique captures a process that commonly causes electrical resistance in materials while, in others, can cause the absence of resistance, or superconductivity December 13th, 2019

How to induce magnetism in graphene: Elusive molecule predicted in the 1970s finally synthesized December 11th, 2019

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project