Utilizing a single atom magnet and oscillating electric fields to coherently drive magnetic resonance in single atoms

On the magnetic bistability of small iron clusters used in scanning tunneling microscopy tip preparation

“…Notably, these clusters exhibit the highest barrier value aligning with the previously observed trend in lanthanides and single ions magnets [35,36]. With the recent increase in ESR-STM studies adopting the same strategy to make a tip [16,17,34,[37][38][39][40][41][42][43][44], we anticipate that our work helps to rationalize why this approach is successful.…”

Implementation of Topological Quantum Gates in Magnet-Superconductor Hybrid Structures

“…The necessary local control to rotate individual magnetic moments in assemblies of magnetic adatoms was recently demonstrated using ESR-STM techniques [17][18][19] with spin-lattice relaxation times of the order of tens of nanoseconds, which are 4 to 5 orders of magnitude longer than the electronic time scales considered here, such that the motion of the magnetic moments can be considered coherent. Moreover, to rotate magnetic moments in opposite direction (as required to create an antiferromagnetic in-plane alignment) can be achieved by using different types of magnetic adatoms, or by changing the local magnetic structure [18,19]. Below, we demonstrate that we can create topological MSH networks even for two different types of magnetic adatoms, resulting in different values of JS, thus opening a path to switching the magnetic structure locally between out-of-plane ferromagnetic and in-plane antiferromagnetic.…”

“…In this article, we advance solutions to both of these important challenges by proposing magnet-superconductor hybrid (MSH) systems, consisting of networks of magnetic adatoms placed on the surface of s-wave superconductors, as a new versatile platform for the implementation of topological quantum gates using Majorana zero modes. Such systems can be built using atomic manipulation techniques [16], and possess the great advantage that their local, atomic scale magnetic structure can be manipulated using a combination of electron-spin resonance and scanning tunneling microscopy (ESR-STM) techniques, as was recently demonstrated for magnetic dimers and trimers [17][18][19]. We propose that the latter can be used to switch segments of the MSH system between trivial and topological phases, thus facilitating the braiding of MZMs and enabling the realization of topological √ σ z -, σ z -and σ x -quantum gates.…”

“…Finally, we note that though we considered dense MSH networks, in which neighboring sites are occupied by magnetic adatoms, we find that topological networks can also be created by using sparser arrangements of magnetic adatoms, occupying only every second or even third site. Such sparser networks might facilitate the use of ESR-STM techniques [17][18][19] to manipulate the local electronic structure. Our results thus represent the proof of concept that the qualitatively new approach to realizing topological quantum gates through a combination of atomic manipulation techniques to quantum engineer MSH structures, and of ESR-STM techniques to implement gate protocols, yields a versatile platform for the realization of topological quantum gates.…”