Engineering the eigenstates of coupled spin-1/2 atoms on a surface

Abstract

Quantum spin networks having engineered geometries and interactions are eagerly pursued for quantum simulation and access to emergent quantum phenomena such as spin liquids. Spin-1/2 centers are particularly desirable because they readily manifest coherent quantum fluctuations. Here we introduce a controllable spin-1/2 architecture consisting of titanium atoms on a magnesium oxide surface. We tailor the spin interactions by atomic-precision positioning using a scanning tunneling microscope (STM), and subsequently perform electron spin resonance (ESR) on individual atoms to drive transitions into and out of quantum eigenstates of the coupled-spin system. Interactions between the atoms are mapped over a range of distances extending from highly anisotropic dipole coupling, to strong exchange coupling. The local magnetic field of the magnetic STM tip serves to precisely tune the superposition states of a pair of spins. The precise control of the spin-spin interactions and ability to probe the states of the coupled-spin network by addressing individual spins will enable exploration of quantum many-body systems based on networks of spin-1/2 atoms on surfaces.

References in corpus (3)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Reading and Writing Single-Atom Magnets
• Fractional excitations in the square-lattice quantum antiferromagnet

Cited by in corpus (8)

• Tuning the exchange bias on a single atom from 1 mT to 10 T
• Harnessing the Quantum Behavior of Spins on Surfaces
• Electron paramagnetic resonance of alkali metal atoms and dimers on ultrathin MgO
• A cotunneling mechanism for all-electrical Electron Spin Resonance of single adsorbed atoms
• A theoretical review on the single-impurity electron spin resonance on surfaces
• Impurity-induced resonant spinon zero modes in Dirac quantum spin-liquids
• Experimental Determination of a Single Atom Ground State Orbital through Hyperfine Anisotropy
• Theory of Electron Spin Resonance Scanning Tunneling Microscopy: The First Decade