Qubits are the building blocks of quantum computers and hold immense promise for revolutionizing computation. However, their delicate nature renders their control and manipulation a significant challenge.
A popular realization of silicon spin qubits uses nanomagnets to provide a magnetic field gradient. Nevertheless, this poses a significant fabrication challenge, as the gradient needs to be as homogenous and reproducible as possible.
A team led by Prof. Martino Poggio (Poggio Lab, University of Basel) reported on a unique combination of fabrication and characterization techniques to address this challenge. They fabricated Cobalt nanomagnets by focused electron beam deposition (FEBID).
FEBID is a ground-breaking, resist-free nanofabrication method. Their findings reveal that FEBID nanomagnets possess unique properties that, in combination with the ability of FEBID to produce 3D magnetic geometries, enable unprecedented optimization possibilities to fabricate nanomagnets for spin qubit control.
Crucial for this work was the ability to accurately characterize the nanomagnets. By using the Qnami ProteusQ, the lead author Liza Zaper (PhD Student in Poggio Lab and Application Scientist at Qnami), was able to investigate their magnetic properties under large in-plane bias fields of up to 200 mT.
Using the Qnami Quantum Microscope, Zaper could not only measure large magnetic field gradients but also reveal small distortions of this gradient – both instrumental in this work, published in ACS Applied Nano Materials.
