Search

Nuclear magnetic resonance spectroscopy is a powerful technique that can identify the presence of certain atoms in a sample by their magnetic properties. Müller et al.now take this concept to its ultimate limit by measuring individual nuclear spins near the surface of diamond.

Large-scale quantum information processing requires the continuous protection of quantum states against errors. Here, the authors demonstrate active quantum error correction that improves the dephasing time of quantum states using a diamond quantum processor.

Repeated observations of quantum states inhibit coherent evolution through the Zeno effect, providing opportunities for controlling multi-qubit systems. Here the authors demonstrate that projecting joint observables of three spins in diamond creates quantum Zeno subspaces that suppress dephasing.

The ability to characterize large and complex nuclear-spin networks could enable quantum applications, such as quantum simulations of many-body physics. Here the authors develop a high-resolution quantum-sensing method and use it to image a network of 50 nuclear spins surrounding a single NV center in diamond.

The use of optically addressable spins to control dark electron-spins is promising for multi-qubit platforms; however, control over darks spins has remained challenging. Here, the authors realize entanglement between individual dark spins associated with substitutional nitrogen defects in diamond.

A hybrid solid-state platform based on two strongly interacting dipolar species is used to study the emergence of the classical properties of a solid from its underlying microscopic quantum description.

An individual electron is used as a quantum sensor to realize atomic-scale magnetic resonance imaging.

Phase-estimation algorithms applied to single nitrogen nuclear spins in diamond allow weak magnetic fields to be measured with high sensitivity and a large dynamic range.

Nitrogen–vacancy centres in diamond have emerged as a promising platform for quantum information processing at room temperature. Now, coherent coupling between two electron spins separated by almost 10 nm has been demonstrated. At this distance, the spins can be addressed individually, which might enable the construction of a network of connected quantum registers.

A Bell experiment that is ‘loophole’ free—leaving no room for explanations based on experimental imperfections—reveals a statistically significant conflict with local realism

Coherent transfer of an optical photon polarization state to a single nuclear spin in a nitrogen–vacancy defect centre in diamond is demonstrated without a high-finesse cavity. A storage time of 10 s is achieved with a transfer fidelity of 98%.

Entanglement of two electron spin qubits in diamond with a spatial separation of three metres is reported; such entanglement can be combined with recently achieved initialization, readout and entanglement operations on local long-lived nuclear spin registers, and paves the way for deterministic long-distance teleportation, quantum repeaters and extended quantum networks.

The coherence of quantum registers is limited by unwanted interactions, both between the qubits and with the environment. Here the authors extend the coherence time of a nitrogen-vacancy centre beyond a second by characterizing and decoupling its interactions with a multi-qubit nuclear spin environment.

Quantum sensing based on solid-state spins can be improved with the use of adaptive strategies.

Quantum measurements affect the state of the system, so they can be used both as probe and control knob. This idea is demonstrated in an experiment with nuclear spin qubits in diamond that are manipulated by measurements alone.

Diffraction conventionally limits the length scale on which spins can be optically probed. A new technique that uses doughnut-shaped beams of light to select just one nitrogen-vacancy centre, by suppressing the fluorescence from those around it, enables single-spin detection, imaging and manipulation with nanoscale resolution.

By using a five-qubit error-correcting code with a recently discovered flag protocol, a logical qubit that is operated fault-tolerantly is realized based on solid-state spin qubits in diamond.

Nitrogen vacancy (NV) centres in diamond can be used for NMR spectroscopy, but increased sensitivity is needed to avoid long measurement times. Kehayias et al. present a nanostructured diamond grating with a high density of NV centres, enabling NMR spectroscopy of picoliter-volume solutions.

Nitrogen-vacancy colour centres in diamond are promising examples for solid-state multi-spin-qubit systems. Here, the spin environment of nitrogen vacancy centres is studied spectroscopically, uncovering a mechanism for spin-flip suppression that opens the way for quantum information applications.

An optical parametric oscillator in the telecom wavelength range is realized in a diamond system consisting of a ring resonator coupled to a diamond waveguide. Threshold powers as low as 20 mW are measured and up to 20 new wavelengths are generated from a single-frequency pump laser.