No 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.

Thoracoscopic sympathectomy is a safe and effective alternative treatment for palmaris hyperhidrosis. Compensatory sweating occurs in more than 50% of patients but is tolerable in most. The majority of patients are satisfied with their short-term outcomes.

No abstract

Scanning tunneling microscopy (STM) enables the bottom-up fabrication of tailored spin systems on a surface that are engineered with atomic precision. When combining STM with electron spin resonance (ESR), these single atomic and molecular spins can be controlled quantum-coherently and utilized as electron-spin qubits. Here we demonstrate universal quantum control of such a spin qubit on a surface by employing coherent control along two distinct directions, achieved with two consecutive radio-frequency (RF) pulses with a well-defined phase difference. We first show transformations of each Cartesian component of a Bloch vector on the quantization axis, followed by ESR-STM detection. Then we demonstrate the ability to generate an arbitrary superposition state of a single spin qubit by using two-axis control schemes, in which experimental data show excellent agreement with simulations. Finally, we present an implementation of two-axis control in dynamical decoupling. Our work extends the scope of STM-based pulsed ESR, highlighting the potential of this technique for quantum gate operations of electron-spin qubits on a surface.