A Fully Voltage-Controlled Spin Logic Device

An important goal in electronics is to reduce power use without sacrificing performance. In spintronics this can be accomplished by increasing the rate of charge to spin conversion. We show that one of the most efficient means of converting charge to spin information uses a topological insulator and voltages instead of currents.

Approach —

• An insulating magnetic layer has an interface with a topological insulator.
• This can open a gap in the topological insulator surface states, making the material insulating.
• A voltage applied to the topological insulator exerts a large force on the magnet, reorienting its magnetization in less than a nanosecond.
• We show that a full set of logic functions can be implemented with such an approach.
• Our modeling shows energy per switch of ~20 atto-Joules and delay less than 500 ps --> a 10x performance improvement compared to state-of-the-art spin devices.