Double Electron Spin Resonance of Engineered Atomic Structures on a Surface

Abstract

Atomic-scale control of multiple spins with individual addressability enables the bottom-up design of functional quantum devices. Tailored nanostructures can be built with atomic precision using scanning tunneling microscopes, but quantum-coherent driving has thus far been limited to a spin in the tunnel junction. Here we show the ability to drive and detect the spin resonance of a remote spin using the electric field from the tip and a single-atom magnet placed nearby. Read-out was achieved via a weakly coupled second spin in the tunnel junction that acted as a quantum sensor. We simultaneously and independently drove the sensor and remote spins by two radio frequency voltages in double resonance experiments, which provides a path to quantum-coherent multi-spin manipulation in customized spin structures on surfaces. One-Sentence Summary: Using a scanning tunneling microscope, we simultaneously control two spins using one tip, paving the way for multi-spin-qubit operations on surfaces.

Harnessing the Quantum Behavior of Spins on Surfaces

“…[ 33 ] The simultaneous control of two electron spins in an engineered atomic structure has recently been realized, shedding light on the debated ESR‐STM driving mechanism and showing the potential for multi‐spin quantum protocols on a surface. [ 37 ]…”

Electrically detected single-spin resonance with quantum spin Hall edge states

“…Larger values of have been achieved using ESR-STM, where several different driving mechanisms other than the Zeeman interaction with the ac field have been proposed [41][42][43][44]. For Ti-H on MgO, and an S = 1/2 spin system, ac magnetic fields up to 1 mT have been reported [40], with an induced Rabi frequency /2π ∼ 10 MHz in continuous mode, while Rabi frequencies up to 30 MHz have been demonstrated in pulsed ESR-STM [45] or using double resonance under large ac voltages [46]. Moreover, these conditions can be achieved while keeping the 2 T 1 T 2 factor larger than one [46][47][48].…”

“…For Ti-H on MgO, and an S = 1/2 spin system, ac magnetic fields up to 1 mT have been reported [40], with an induced Rabi frequency /2π ∼ 10 MHz in continuous mode, while Rabi frequencies up to 30 MHz have been demonstrated in pulsed ESR-STM [45] or using double resonance under large ac voltages [46]. Moreover, these conditions can be achieved while keeping the 2 T 1 T 2 factor larger than one [46][47][48]. These rates translate into maximal currents up to ∼3 pA,…”

Electrically-detected single-spin resonance with Quantum Spin Hall edge states

“…[41][42][43][44] For Ti-H on MgO, and S = 1/2 spin system, AC magnetic fields up to 1 mT have been reported, 40 with an induced Rabi frequency Ω/2π ∼ 10 MHz in continuous mode, while Rabi frequencies up to 30 MHz have been demonstrated in pulsed ESR-STM 45 or using double resonance under large AC voltages. 46 Moreover, these conditions can be achieved while keeping the Ω 2 T 1 T 2 factor larger than one. [46][47][48] These rates translates into maximal currents up to ∼3 pA, 11) is an upper bound for the pumped current generated by the single-spin resonance.…”

“…46 Moreover, these conditions can be achieved while keeping the Ω 2 T 1 T 2 factor larger than one. [46][47][48] These rates translates into maximal currents up to ∼3 pA, 11) is an upper bound for the pumped current generated by the single-spin resonance. In addition to the conditions leading to this maximum current (β ω 0 1 and Ω 2 T 1 T 2 1), there are a few factors that could reduce the efficiency of this resonant pumping.…”