Tunable magnetless optical isolation with twisted Weyl semimetals.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Photonics

Background:

• Weyl semimetals possess unique topological properties enabling nonreciprocal magneto-optical effects.
• These effects can be achieved without external magnetic fields, promising miniaturized and energy-efficient optical components.
• The inherent topological robustness of Weyl semimetals limits their tunability for practical applications.

Purpose of the Study:

• To enhance the tunability of Weyl semimetal responses for optical applications.
• To design and demonstrate a novel approach for creating tunable optical isolators.
• To overcome the limitations of intrinsic topological robustness in Weyl semimetals.

Main Methods:

• Utilizing multilayered configurations of twisted anisotropic Weyl semimetals.
• Implementing a design based on controlled and reversible isolation by adjusting the twist angle between layers.
• Testing the device in the Faraday geometry within the mid-infrared (mid-IR) frequency range.

Main Results:

• Achieved isolation exceeding 50 dB with minimal insertion loss of 0.33 dB.
• Demonstrated significant reduction in device dimensions by eliminating conventional polarizers due to in-plane anisotropy.
• Showcased controlled and reversible tunability by altering the twist angle.

Conclusions:

• The proposed multilayered twisted Weyl semimetal design offers a highly adaptable and ultra-compact solution for optical isolators.
• This advancement is crucial for the development of integrated photonics and quantum technology.
• The approach overcomes previous limitations, enabling new possibilities in optical device engineering.