Long spin relaxation times in a transition metal atom in direct contact to a metal substrate

TL;DR

This study demonstrates that iron atoms on a platinum substrate exhibit unexpectedly long spin relaxation times in the nanosecond range, enabling potential applications in spin-based data storage and processing.

Contribution

It reveals that transition metal atoms can have long spin relaxation times directly on a conductive substrate, challenging previous assumptions about rapid relaxation.

Findings

Iron atoms on platinum have nanosecond spin relaxation times.

Long relaxation times are comparable to decoupled atoms.

Strong coupling to conduction electrons is maintained.

Abstract

Long spin relaxation times are a prerequisite for the use of spins in data storage or nanospintronics technologies. An atomic-scale solid-state realization of such a system is the spin of a transition metal atom adsorbed on a suitable substrate. For the case of a metallic substrate, which enables directly addressing the spin by conduction electrons, the experimentally measured lifetimes reported to date are on the order of only hundreds of femtoseconds. Here, we show that the spin states of iron atoms adsorbed directly on a conductive platinum substrate have an astonishingly long spin relaxation time in the nanosecond regime, which is comparable to that of a transition metal atom decoupled from the substrate electrons by a thin decoupling layer. The combination of long spin relaxation times and strong coupling to conduction electrons implies the possibility to use flexible coupling schemes in order to process the spin-information.