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An optically addressable fluorescent-protein spin qubit is realized using enhanced yellow fluorescent protein; the qubit can be coherently controlled at liquid-nitrogen temperatures and the spin detected at room temperature in cells.

Silicon carbide is a polymorphic material with over 250 known crystal structures. Here the authors show that such polymorphism can be used as a degree of freedom for engineering optically addressable and coherently interacting spin states, including many with room-temperature quantum coherence.

Controlling and monitoring individual spins is desirable for building spin-based devices. The optical manipulation of the spin of manganese ions in gallium arsenide is now possible. The spins of a small number of ions can be oriented by selecting the polarization of a laser beam. Reduction of the ion concentration enables control of single manganese spins.

A nitrogen impurity in diamond—where two of the carbon atoms are replaced by a nitrogen atom and a vacant lattice site—is seen as a valuable qubit. The spin of an electron localized to the nitrogen-vacancy centre is commonly used for processing. Researchers now show that this electron spin state can be transferred to the nitrogen nuclear spin, where it can be stored until needed.

Dynamic strain in silicon carbide can tune point defect properties and coherently control their electron spins. Here the authors fabricate Gaussian-shaped surface acoustic wave transducers, use stroboscopic x-ray imaging to measure lattice dynamics, and observe its effects on defect photoluminescence.

Development of diamond-based quantum and electronic technologies requires heterogeneous integration, which has remained challenging. This work realizes direct bonding of single crystal diamond membranes to a broad range of technology-relevant substrates while maintaining quantum coherence for hosted qubits.

Improving the performance and scalability of quantum nodes is of paramount importance to expedite the development of quantum technologies. Here the authors demonstrate fiber-coupled 1D PhC cavities with high photon extraction efficiency, and optical coupling between a single SiV center and such a cavity.

Researchers show that atom-like dipoles based on germanium vacancy centres in diamond may be useful as antennas, exhibiting million-fold near-field optical intensity enhancement. These antennas are used to detect and control the charge state of nearby carbon vacancies.

The axis of a spinning electron tends to remain fixed in direction: in contrast, an electron moving in a semiconductor sees a lattice of charged atoms flying past, causing its spin direction to fluctuate. Koralek and colleagues demonstrate that an electric field applied to the semiconductor can balance this spin-destabilizing effect; the collective spin of the entire gas of electrons is conserved, a property well-suited for 'spintronics' applications.

The generation of an electric voltage from a heat gradient is demonstrated for the first time in the ferromagnetic semiconductor GaMnAs. This allows flexible design of the magnetization directions, a large spin polarization, and measurements across the magnetic phase transition. The effect is observed even in the absence of longitudinal charge transport.

When current is passed through certain semiconductors or metals, spins of opposite sign accumulate on opposing boundaries. The phenomenon is known as the spin Hall effect, and now, for the first time, its dynamics has been measured directly.

A nanomechanical interface between optical photons and microwave electrical signals is now demonstrated. Coherent transfer between microwave and optical fields is achieved by parametric electro-optical coupling in a piezoelectric optomechanical crystal, and this on-chip technology could form the basis of photonic networks of superconducting quantum bits.

Seamless integration of decoherence protection into quantum logic gates has enabled high-fidelity execution of a quantum algorithm with individual spins in a hybrid quantum system.

The length of time a qubit can store information is linked to its coherence time. Here, the authors demonstrate that industrially important crystals comprising more than one species can host qubits with unexpectedly long coherence times.

Single nitrogen–vacancy centres in diamond are a prime candidate for implementing scalable quantum information processing at room temperature. Work so far has been focused on using the ground state of these defects, but an experimental study now suggests that the excited state is a promising route to fast gate operation.

A non-classical superposition of zero- and one-phonon mechanical Fock states is generated and measured by strongly coupling a surface acoustic-wave resonator to a superconducting qubit.

Isotope engineering of silicon carbide leads to control of nuclear spins associated with single divacancy centres and extended electron spin coherence.

The authors use surface acoustic waves, focused in a Gaussian geometry, to manipulate the spin state of divacancy defects in silicon carbide via mechanical driving. They demonstrate that shear strain is important in controlling the spin transitions.

Two-dimensional magnetic resonance imaging of hydrogen in organic samples with a resolution of 12 nm can be achieved by using the spin of a nitrogen–vacancy centre in diamond as a sensor.

Certain point defects in crystals can be used as optically addressable quantum bits, much like atoms trapped in vacuum. Ivády et al. show that embedding such artificial atoms in stacking faults can actually improve their optical properties, making them function even more like true atoms.

Solid-state systems are established candidates to study models of many-body physics but have limited control and readout capabilities. Ensembles of defects in diamond may provide a solution for studying dipolar systems.

Control of the directional photocurrent by polarized light in topological insulators may enable topological spintronics but is not yet well understood. Here the authors demonstrate that the directional photocurrent is due to the asymmetric optical transitions between topological surface states and bulk states.

An all-optical manipulation of the Berry phase based on stimulated Raman adiabatic passage is demonstrated in an individual nitrogen–vacancy centre in diamond. The adiabatic control is 100 times faster than that demonstrated before in atomic systems.

Optically detected magnetic resonance experiments show that single spins having a coherence time on the millisecond scale can be isolated in divacancy defects in silicon carbide at low temperature.

Defects in silicon carbide represent a viable candidate for realization of spin qubits. Here, the authors show stable bidirectional charge state conversion for the silicon vacancy and divacancy, improving the photoluminescence intensity by up to three orders of magnitude with no effect on spin coherence.