A new hybrid circuit can turn a permanent magnet off using almost zero power, acting like a transistor for magnetic fields.
Permanent magnets are useful because they do not need power, but they are annoying because you cannot easily switch them on and off. The Saturable Electronic Reluctance Switch (SERS) solves this by using a small electrical pulse to redirect the magnetic field. This allows engineers to get the strength of a permanent magnet with the control of an electromagnet. It uses far less power and creates much less noise than traditional methods, which is perfect for the sensitive environment of a quantum computer. This device could finally allow us to scale up quantum hardware without it overheating. It is a major upgrade for any technology that relies on precise, switchable magnetic control.
The Saturable Electronic Reluctance Switch: Switchable low-power and low-noise generation of magnetic fields using permanent magnets
arXiv · 2605.05158
Across many areas of science, there is a need to generate magnetic fields that are both ultra-stable and switchable on and off. While permanent and superconducting magnets offer exceptionally low-noise fields, they are not readily switchable. Conversely, electromagnets are switchable but are susceptible to current noise. We present a hybrid technique to switch the field of any arbitrary magnet through use of a non-linear ferromagnetic circuit, named the Saturable Electronic Reluctance Switch (SE