High Quality Factor Graphene-Based Two-Dimensional Heterostructure Mechanical Resonator

Area of Science:

• Materials Science
• Condensed Matter Physics
• Quantum Technology

Background:

• Ultralight mechanical resonators are crucial for detecting minute forces and mass changes.
• Low-dimensional materials offer excellent transduction but face challenges with resistive losses and heating.
• Combining different two-dimensional (2D) materials presents a novel approach to overcome these limitations.

Purpose of the Study:

• To fabricate and characterize a novel heterostructure mechanical resonator.
• To investigate the potential of combining niobium diselenide (NbSe2) and graphene for improved resonator performance.
• To assess the resonator's suitability for integration into quantum circuits.

Main Methods:

• Fabrication of a heterostructure resonator using few layers of NbSe2 encapsulated by graphene sheets.
• Measurement of mechanical resonator quality factors at low temperatures.
• Characterization of electrical losses and low-temperature dependence of the intrinsic quality factor.
• Coupling the resonator to a superconducting cavity for high-sensitivity readout.

Main Results:

• The hybrid resonator achieved high quality factors up to 245,000 at low temperatures.
• Reduced electrical losses were observed compared to few-layer graphene resonators, attributed to NbSe2's lower resistivity.
• The low-temperature dependence of the quality factor indicated dissipation via two-level systems interacting with the electronic system.
• Successful integration with a superconducting cavity enabled high-sensitivity readout.

Conclusions:

• The NbSe2-graphene heterostructure resonator offers a promising solution for minimizing losses in ultralight mechanical systems.
• This hybrid approach enhances the performance of 2D material-based resonators.
• The developed resonator is a sensitive, low-loss transducer suitable for integration into future quantum circuits and technologies.