title: High-efficiency resonant amplification of weak magnetic fields for single spin magnetometry at room temperature.
abstract: Magnetic resonance techniques not only provide powerful imaging tools that have revolutionized medicine, but they have a wide spectrum of applications in other fields of science such as biology, chemistry, neuroscience and physics. However, current state-of-the-art magnetometers are unable to detect a single nuclear spin unless the tip-to-sample separation is made sufficiently small. Here, we demonstrate theoretically that by placing a ferromagnetic particle between a nitrogen-vacancy magnetometer and a target spin, the magnetometer sensitivity is improved dramatically. Using materials and techniques that are already experimentally available, our proposed set-up is sensitive enough to detect a single nuclear spin within ten milliseconds of data acquisition at room temperature. The sensitivity is practically unchanged when the ferromagnet surface to the target spin separation is smaller than the ferromagnet lateral dimensions; typically about a tenth of a micrometre. This scheme further benefits when used for nitrogen-vacancy ensemble measurements, enhancing sensitivity by an additional three orders of magnitude.
authors.affiliation: Department of Physics, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland.
authors.forename: Luka
authors.initials: L
authors.lastname: Trifunovic
authors.affiliation: 1] Department of Physics, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland [2] JARA Institute for Quantum Information, RWTH Aachen University, Aachen D-52056, Germany.
authors.forename: Fabio L
authors.initials: FL
authors.lastname: Pedrocchi
authors.affiliation: Department of Physics, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland.
authors.forename: Silas
authors.initials: S
authors.lastname: Hoffman
authors.affiliation: Department of Physics, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Maletinsky
authors.affiliation: 1] Department of Physics, Harvard University, Cambridge Massachusetts 02138, USA [2] Condensed Matter Chair, Department of Physics and Astronomy, University of Waterloo, Canada.
authors.forename: Amir
authors.initials: A
authors.lastname: Yacoby
authors.affiliation: Department of Physics, University of Basel, Klingelbergstrasse 82, Basel CH-4056, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Loss
mesh_terms: D000669:Amplifiers, Electronic; D004867:Equipment Design; D019544:Equipment Failure Analysis; D060526:Magnetic Fields; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000528:radiation effects; D060306:Magnetometry / Q000295:instrumentation*; D059346:Magnets; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D036103:Nanotechnology / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013113:Spin Labels
chemical_list: D058185:Magnetite Nanoparticles; D013113:Spin Labels