Field-free superconducting diode effect in noncentrosymmetric superconductor/ferromagnet multilayers

Area of Science:

• Condensed Matter Physics
• Materials Science
• Superconductivity

Background:

• Conventional semiconductor diodes exhibit high resistivity at low temperatures, leading to energy loss and heating.
• The superconducting diode effect (SDE) offers a potential solution by enabling zero-resistance current flow in one direction.
• Existing SDE implementations often require external magnetic fields, limiting practical applications.

Purpose of the Study:

• To present a novel implementation of the zero-field superconducting diode effect (SDE).
• To explore the tunability and control of SDE in artificially stacked multilayers.
• To enable the development of energy-loss-free electronic devices.

Main Methods:

• Fabrication of noncentrosymmetric [Nb/V/Co/V/Ta]20 multilayers.
• Utilizing magnetic layers within the multilayers to break inversion symmetry.
• Investigating the influence of structural parameters (element type, thickness, stacking order) on SDE.
• Controlling SDE polarity via the magnetization direction of ferromagnetic layers.

Main Results:

• Successful demonstration of zero-field SDE in the fabricated multilayers.
• Tunable SDE characteristics achieved by adjusting structural parameters.
• Polarity of the SDE was successfully controlled by manipulating magnetization direction.
• Compatibility with microfabrication techniques and potential integration with Josephson junctions.

Conclusions:

• The developed multilayered structure provides a viable platform for realizing the zero-field SDE.
• This approach overcomes the limitation of external magnetic field requirements for SDE.
• The energy-loss-free SDE has significant implications for future non-volatile memories and ultralow power logic circuits.