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Controllable two-qubit interactions are necessary to build a functional quantum computer. Here the authors demonstrate fast, coherent swapping of two spin states mediated by a long, multi-electron quantum dot that could act as a tunable coupler mediating interactions between multiple qubits.

Hybrid superconductor-semiconductor devices offer a promising platform for topological superconductivity. Here, Ke and Moehle et al. create ballistic Josephson junctions in InSb quantum wells and use magnetic and electric fields to control their free energy landscape.

In the quantum Hall regime, strong interactions lead to the formation of unconventional spatially ordered electronic states. Qian et al. present evidence for a progressive sequence of transitions from isotropic through nematic to smectic phases in half-filled quantum Hall states.

Theories predict teleportation of phase-coherent single electrons through a topological superconducting island. Here, the authors report persistent Coulomb blockade conductance peaks due to coherent transport of single electrons through patterned InAs-Al islands embedded in an Aharonov-Bohm interferometer.

Hydrostatic pressure is used as a means to tune the two-dimensional electron gas hosted in a GaAs/AlGaAs crystal from a topologically ordered to a spontaneously broken symmetry phase.

An artificial Kitaev chain is realized by engineering three coupled quantum dots in a two-dimensional electron gas, which enables the manipulation and observation of both the edge and bulk states.

Information transfer between distant qubits suffers from spurious interactions and disorder. Here, the authors report up to an order of magnitude enhancement in the quality factor of a swap operation of eigenstates in a quantum dot chain, by using a periodic driving protocol inspired by discrete time crystals.

Scalable gate tunable superconducting qubits can be realized using a proximitized InAs two-dimensional electron gas.

Quantum Hall interferometers have proven to be a useful platform for the study of fractional statistics. Here, the authors experimentally study the effect of Coulomb interactions between bulk and edge charges on the interferometer behavior, validating previous theoretical predictions.

It has been predicted that longitudinal coupling between a qubit and a superconducting resonator can mediate efficient interactions among distant qubits. Here the authors implement such a coupling between a singlet-triplet qubit in a semiconductor double quantum dot and a high-impedance superconducting resonator.

The authors study the intrinsic superconducting diode effect (SDE) in a single Josephson junction consisting of a InGaAs/InAs/InGaAs quantum well as the weak link, and an Al film as the superconductor. They find a correspondence between SDE and an offset in the relationship between critical current and the difference in phase of the superconducting order parameter across the junction.

A sudden inversion of the supercurrent diode effect is revealed in both inductance and critical current measurements in ballistic Josephson junctions. A simple analytical model shows that the inversion is associated with a ground state jump, the elusive 0−π-like transition.

Nuclear spins in gallium arsenide produce noise at discrete frequencies, which can be notch-filtered efficiently to extend coherence times of electron spin qubits to nearly 1 ms.

Previous demonstrations of spin state transfer in quantum dot chains relied on physical motion of electrons or sequences of SWAP operations. Here, the authors implement an alternative method based on adiabatic evolution, offering advantages in terms of implementation and robustness to noise and errors.

Despite recent demonstrations of coherent spin-state transfer in arrays of spin qubits via exchange interaction, all-matter spin-state teleportation is still out of reach. Here the authors provide evidence for conditional teleportation of quantum-dot spin states, entanglement swapping, and gate teleportation.

Electron-electron scattering plays a crucial role in many solid state phenomena; however, the direct measurement of electron-electron scattering length is challenging. Here, the authors use transverse magnetic focusing to measure this quantity in high-mobility GaAs/AlGaAs heterostructures.

A platform based on complementary metal–oxide–semiconductor (CMOS) technology operating with qubits close to 100 mK can generate static and dynamic signals for the control of many qubits.

An interferometer device demonstrates the interference of fractional quantum Hall effect edge states. This is a big step towards braiding non-Abelian anyons.

Two-dimensional electron systems at half-filled Landau levels can form unusual electronic states such as paired fractional quantum Hall and nematic phases. Here the authors observe the transition between these two phases at filling factors 5/2 and 7/2 and demonstrate the important influence of interactions.

An interferometer device is used to detect the quantum-mechanical phase that is gained when two anyons are braided around each other. The fractional value of the phase proves that these quasiparticles are neither bosons nor fermions.

Transmission of single-spin and entangled quantum states without the physical displacement of electrons is demonstrated in a quadruple quantum dot array using the Heisenberg exchange interaction and coherent SWAP gates.

Evidence is found for phase-tunable Majorana zero modes in scalable two-dimensional Josephson junctions produced by top-down fabrication.

Hybrid devices of superconductors and semiconductor nanowires may be topological and host majorana. This Perspective summarizes the current situation of the field, and highlights the developments in materials science required to make progress.