A CMOS-compatible, scalable and compact magnetoelectric spin-torque microwave detector.

Area of Science:

• Spintronics and Microwave Technology
• Materials Science and Engineering

Background:

• Compact and sensitive microwave detectors compatible with CMOS processes are a significant challenge.
• Spin-torque diodes offer superior sensitivity over Schottky diodes but require external antennas.
• Existing technologies lack monolithic integration for efficient wireless signal detection.

Purpose of the Study:

• To develop a compact, highly sensitive microwave detector by integrating magnetoelectric antennas with spintronic devices.
• To demonstrate a monolithic device capable of directly converting wireless signals to a DC output.
• To investigate the scalability and performance enhancement through arrays of magnetic tunnel junctions.

Main Methods:

• Fabrication of a monolithic magnetoelectric (ME) spin-torque microwave detector integrating a ME antenna and a magnetic tunnel junction (MTJ).
• Characterization of the device's sensitivity, noise equivalent power, and footprint.
• Investigation of the underlying physics involving non-linear coupling between magnetization dynamics and ME antenna effects.
• Demonstration of scalability by integrating a ME antenna with an array of MTJs.

Main Results:

• Achieved a sensitivity exceeding 90 kV/W with a noise equivalent power of 3 pW/Hz^-1/2 in a 0.4 mm² footprint.
• Demonstrated direct conversion of wireless electromagnetic signals to a DC output at sub-microwatt power levels.
• Showcased scalability, with a four-MTJ detector achieving sensitivity over 400 kV/W.

Conclusions:

• The developed ME spin-torque microwave detector offers a significant advancement in sensitivity and compactness.
• The monolithic integration of ME antennas and MTJs overcomes limitations of previous designs.
• This technology holds promise for a new generation of highly sensitive, scalable microwave detectors for various applications.