Abstract
Methods to selectively detect and manipulate nuclear spins by single electrons of solid-state defects play a central role for quantum information processing and nanoscale nuclear magnetic resonance (NMR). However, with standard techniques, no more than eight nuclear spins have been resolved by a single defect centre. Here we develop a method that improves significantly the ability to detect, address and manipulate nuclear spins unambiguously and individually in a broad frequency band by using a nitrogen-vacancy (NV) centre as model system. On the basis of delayed entanglement control, a technique combining microwave and radio frequency fields, our method allows to selectively perform robust high-fidelity entangling gates between hardly resolved nuclear spins and the NV electron. Long-lived qubit memories can be naturally incorporated to our method for improved performance. The application of our ideas will increase the number of useful register qubits accessible to a defect centre and improve the signal of nanoscale NMR.
Highlights
Methods to selectively detect and manipulate nuclear spins by single electrons of solid-state defects play a central role for quantum information processing and nanoscale nuclear magnetic resonance (NMR)
We show how one can individually address nuclear spins to perform high-fidelity two-qubit quantum gates between the NV electron qubit and the addressed nuclear qubit in a robust way, even when they are hardly resolved in spectrum
When the radio frequency (RF) driven rotation does not commute with the effective interaction Hamiltonian, it breaks the erasing process of delayed entanglement echo on the target spins, and thereby, we address the nuclear spins in a highly selective way
Summary
Methods to selectively detect and manipulate nuclear spins by single electrons of solid-state defects play a central role for quantum information processing and nanoscale nuclear magnetic resonance (NMR). Standard DD techniques can only be used to address a few nuclear spins because of a number of drawbacks such as low spectral resolution[23], resonance ambiguities[24,25] and perturbations from the electron-nuclear coupling[21] In this respect ENDOR techniques are applied to improve the spectral resolution by measuring the NV signal over long evolution times[23,26,27], but without the abilities of individual spin addressing and control. Note that individual addressing of nuclear spins and the implementation of quantum gates on them are more demanding than nuclear-spin detection, but essential in quantum information processing and thorough characterization of nuclear spins Our method overcomes these difficulties to selectively address specific nuclear spins by applying radio frequency (RF) fields in a delay window, while the entanglement with the electron spin sensor is preserved by a subsequent Hahn echo operation[2]. We show how the efficiency of our method can be enhanced by using a nuclear memory, which has coherence times much larger than the life time of the electron spin of the sensor
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
