Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Capacitor in an AC Circuit01:23

Capacitor in an AC Circuit

2.8K
A capacitor is charged by passing an electric current through it, which causes the plates to start accumulating an electrostatic charge. Since the strength of the charging current is maximum when the capacitor plates are uncharged and gradually decreases exponentially until the capacitor is fully charged, the charging process is neither instantaneous nor linear. The property of a capacitor to store a charge on its plates is called its capacitance.
Consider a purely capacitive circuit consisting...
2.8K
Significance of Displacement Current01:27

Significance of Displacement Current

4.8K
A displacement current is analogous to a real current in Ampère's law, participating in Ampère's law the same way as the usual conduction current. However, it is produced by a changing electric field. Displacement current is defined in terms of a time-varying electric field, and also has an associated displacement current density. By adding a term accounting for displacement current, Maxwell modified the existing Ampère's law, which is now called generalized Ampère's law.
4.8K
Time and frequency -Domain Interpretation of Phase-lead Control01:24

Time and frequency -Domain Interpretation of Phase-lead Control

134
Phase-lead controllers are commonly used in various control systems to enhance response speed and stability. Adjusting the brightness on a television screen offers a practical example of phase-lead control. When contrast is enhanced, a phase-lead controller is employed. Mathematically, phase-lead control is identified when the first parameter is smaller than the second.
The design of phase-lead control involves the strategic placement of poles and zeros to balance steady-state error and system...
134
The de Broglie Wavelength02:32

The de Broglie Wavelength

26.2K
In the macroscopic world, objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle; it will continue traveling in a straight line unless it collides with another ball, or it is acted on by some other force, such as friction. The ball has a well-defined position and velocity or well-defined momentum, p = mv, which is defined by mass m and velocity v at any given moment. This is the typical...
26.2K
Basic Discrete Time Signals01:16

Basic Discrete Time Signals

298
The unit step sequence is defined as 1 for zero and positive values of the integer n. This sequence can be graphically displayed using a set of eight sample points, showing a step function starting from n=0 and remaining constant thereafter.
The unit impulse or sample sequence is mathematically expressed as zero for all n values except at n=0, where it is one. The unit impulse sequence, denoted by δ(n), is the first difference of the unit step sequence, while the unit step sequence u(n) is...
298
Time and frequency -Domain Interpretation of Phase-lag Control01:21

Time and frequency -Domain Interpretation of Phase-lag Control

145
Phase-lag controllers are widely used in control systems to improve stability and reduce steady-state errors. A dimmer switch controlling the brightness of a light bulb serves as a practical example of phase-lag control, gradually adjusting the bulb's brightness. Mathematically, phase-lag control or low-pass filtering is represented when the factor 'a' is less than 1.
Phase-lag controllers do not place a pole at zero, but instead influence the steady-state error by amplifying any...
145

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Outcome associations of CSF total tau in suspected non-Alzheimer pathophysiology.

Journal of neurology·2026
Same author

The microwave phase locking in Bloch transistor.

Nature communications·2026
Same author

Multimodal Biomarker Characterization of the ALS/FTD Spectrum: A Real-World Clinical Dataset Analysis.

International journal of molecular sciences·2025
Same author

Intensity of Intrathecal Total IgG Synthesis in Multiple Sclerosis Correlates with the Degree of Pleocytosis, Diversity of Intrathecal Antiviral Antibody Specificities, and Female Sex.

Antibodies (Basel, Switzerland)·2024
Same author

Cerebrospinal fluid-specific oligoclonal bands in dogs with idiopathic epilepsy.

Journal of veterinary internal medicine·2024
Same author

Quantized current steps due to the synchronization of microwaves with Bloch oscillations in small Josephson junctions.

Nature communications·2024

Related Experiment Video

Updated: Sep 3, 2025

Generation and Coherent Control of Pulsed Quantum Frequency Combs
06:42

Generation and Coherent Control of Pulsed Quantum Frequency Combs

Published on: June 8, 2018

9.1K

Quantized current steps due to the a.c. coherent quantum phase-slip effect.

Rais S Shaikhaidarov1,2, Kyung Ho Kim1, Jacob W Dunstan1

  • 1Royal Holloway, University of London, Egham, UK.

Nature
|July 25, 2022
PubMed
Summary
This summary is machine-generated.

Researchers directly observed dual Shapiro steps in superconducting nanowires, demonstrating quantized current steps. This breakthrough, crucial for quantum current standards, overcomes previous material and engineering challenges.

More Related Videos

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping
14:58

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping

Published on: June 3, 2015

14.9K
Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators
09:23

Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators

Published on: May 30, 2014

14.6K

Related Experiment Videos

Last Updated: Sep 3, 2025

Generation and Coherent Control of Pulsed Quantum Frequency Combs
06:42

Generation and Coherent Control of Pulsed Quantum Frequency Combs

Published on: June 8, 2018

9.1K
Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping
14:58

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping

Published on: June 3, 2015

14.9K
Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators
09:23

Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators

Published on: May 30, 2014

14.6K

Area of Science:

  • Condensed Matter Physics
  • Quantum Metrology
  • Superconductivity

Background:

  • The AC Josephson effect, observed as quantized voltage steps (Shapiro steps), is fundamental to quantum mechanics and voltage standards.
  • The dual effect, AC coherent quantum phase slip (CQPS), involves magnetic flux tunneling and is predicted to manifest as quantized current steps.
  • CQPS is vital for future current standards and closing the quantum metrology triangle, but direct observation of current steps has been elusive.

Purpose of the Study:

  • To directly observe the dual Shapiro steps, or quantized current steps, in a superconducting nanowire.
  • To overcome limitations in materials and circuit engineering that previously prevented the experimental realization of these current steps.
  • To advance the development of quantum current standards.

Main Methods:

  • Fabrication of a superconducting nanowire device using NbN material.
  • Integration of the nanowire into an inductive environment to suppress broadening effects.
  • Experimental measurement of current steps under microwave irradiation up to 26 GHz.

Main Results:

  • Direct observation of sharp, quantized current steps in a superconducting nanowire, analogous to the dual Shapiro steps.
  • Observed steps are clear up to 26 GHz frequency with measured current values of 8.3 nA.
  • The observed phenomenon is attributed to the AC coherent quantum phase slip (CQPS) effect.

Conclusions:

  • The study successfully demonstrates the direct observation of quantized current steps in a superconducting nanowire.
  • This achievement overcomes the long-standing challenge of realizing flat current steps in superconductors, previously hindered by material and circuit limitations.
  • The findings pave the way for practical applications in quantum current standards and complete the quantum metrology triangle.