6 research outputs found
Room-temperature control and electrical readout of individual nitrogen-vacancy nuclear spins
Nuclear spins in semiconductors are leading candidates for quantum
technologies, including quantum computation, communication, and sensing.
Nuclear spins in diamond are particularly attractive due to their extremely
long coherence lifetime. With the nitrogen-vacancy (NV) centre, such nuclear
qubits benefit from an auxiliary electronic qubit, which has enabled
entanglement mediated by photonic links. The transport of quantum information
by the electron itself, via controlled transfer to an adjacent centre or via
the dipolar interaction, would enable even faster and smaller processors, but
optical readout of arrays of such nodes presents daunting challenges due to the
required sub-diffraction inter-site distances. Here, we demonstrate the
electrical readout of a basic unit of such systems - a single 14N nuclear spin
coupled to the NV electron. Our results provide the key ingredients for quantum
gate operations and electrical readout of nuclear qubit registers, in a manner
compatible with nanoscale electrode structures. This demonstration is therefore
a milestone towards large-scale diamond quantum devices with semiconductor
scalability.Comment: 11 pages, 4 figure
Collective strong coupling with homogeneous Rabi frequencies using a 3D lumped element microwave resonator
We design and implement 3D-lumped element microwave cavities that spatially focus on the magnetic fields to a small mode volume. They allow coherent and uniform coupling to electron spins hosted by nitrogen vacancy centers in diamond. We achieve large homogeneous single spin coupling rates, with an enhancement of more than one order of magnitude compared to standard 3D cavities with a fundamental resonance at 3GHz. Finite element simulations confirm that the magnetic field distribution is homogeneous throughout the entire sample volume, with a root mean square deviation of 1.54%. With a sample containing 1E17 nitrogen vacancy electron spins, we achieve a collective coupling strength of Omega=12MHz, a cooperativity factor C=27, and clearly enter the strong coupling regime. This allows to interface a macroscopic spin ensemble with microwave circuits, and the homogeneous Rabi frequency paves the way to manipulate the full ensemble population in a coherent way