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A superlattice consisting of two graphene sheets twisted relative to each other by a specific amount exhibits superconductivity when doped electrostatically, with a relatively high critical temperature.

Moiré systems formed by 2D atomic layers have widely tunable electrical and optical properties and host exotic, strongly correlated and topological phenomena, including superconductivity, correlated insulator states and orbital magnetism. In this Viewpoint, researchers studying different aspects of moiré materials discuss the most exciting directions in this rapidly expanding field.

Emergent phenomena at the interface between a topological insulator and a ferromanget reflect broken symmetry of topological state. Here, Lee et al. report direct measurement of induced magnetism at the Bi₂Se₃-EnS interface, paving the way to understand emergent orders in topological material with broken time reversal symmetry.

Infrared nanoimaging of phonon polaritons in twisted α-phase molybdenum trioxide bilayers reveals tunable wavefront geometries and topological transitions over a broad range of twist angles, offering a configurable platform for nanophotonic applications.

When the two graphene sheets in a van der Waals heterostructure are twisted relative to each other by a specific amount, Mott-like insulating phases are observed at half-filling.

At low temperatures, a superconducting current that flows through a graphene layer sandwiched between two superconducting electrodes can be carried by either electrons or by holes, depending on the gate voltage that determines the charge density in the graphene layer. Interestingly, this finds that a finite supercurrent can flow even when the charge density is zero.

Graphene grain boundaries and charge inhomogeneities limit its electronic properties. Here the authors combine scanning near-field optical microscopy with electrical read-out to image these defects at the nanoscale under an encapsulation layer, and show that charges build up along the edges of the flake.

Graphene multilayers can host heavy electrons in flat bands alongside light electrons in Dirac cones. Local probes now reveal that a finite Dirac electron population persists at the Fermi level while correlated states form in the flat bands.

In 2004, physicists reported something remarkable: they had isolated ultrathin films of carbon atoms using sticky tape alone, and found that the films had astounding properties. The finding would forever change condensed-matter physics.

Aligning magic-angle twisted bilayer graphene to boron nitride layers introduces a gate hysteresis coexisting with its strongly correlated phases. This bistability enables electrical switching between superconducting, metallic and insulating states.

Exploiting the intrinsic response of magic-angle twisted bilayer graphene to resonant terahertz radiation, the interplay between electron interactions and quantum geometry is studied in such flat-band systems.

Trilayer graphene can be realized in two different stacking configurations, known as rhombohedral and Bernal stackings, which display different electronic characteristics. It is now shown that an applied perpendicular electric field can be used to switch between these two configurations.

Van der Waals heterostructures enable fabrication of materials with engineered functionalities. Here, the authors demonstrate precise control over the interaction between layers by application of pressure with a scanning tunnelling microscopy tip.

Single-layer transition metal dichalcogenides have already made their mark in the world of device physics. Twin studies have now found that they exhibit unconventional Ising pair superconductivity.

Transistor devices can be fabricated from exfoliated layers of black phosphorus.

A photocurrent enhancement at the charge neutrality point is observed in graphene when the Fermi level matches the Dirac point.

Interlayer transport can be made to occur slower or faster than intralayer scattering in van der Waals heterostructures, allowing the thermalization pathways for optically excited carriers to be tuned.

Measurements of the superfluid stiffness in twisted trilayer graphene reveal unconventional nodal-gap superconductivity, where the superconducting transition is controlled by phase fluctuations rather than Cooper-pair breaking.

Research on superconductivity in magic-angle twisted bilayer graphene reveals unconventional behaviour, an anisotropic gap and a significant role of quantum geometry, using combined d.c. transport and microwave measurements, suggesting new insights into superconductivity mechanisms.

A graphene-based Josephson junction incorporated in a superconducting circuit forms a voltage-tunable transmon qubit that can be controlled coherently.

Short pulses of light shift the balance between two competing charge density wave phases, allowing the weaker one to manifest transiently while suppressing the stronger one. This shows that competing phases can be tuned in a non-equilibrium setting.

Electrical control of magnetism in a bilayer of CrI₃ enables the realization of an electrically driven magnetic phase transition and the observation of the magneto-optical Kerr effect in 2D magnets.

Three different ultrafast probes investigate a non-adiabatic phase transition and find substantial evidence of topological defects inhibiting the reformation of the equilibrium phase.

Here, twisted boron nitride is demonstrated to be a versatile moiré substrate for band structure engineering.

Trilayer graphene with the layers consecutively twisted by the same angle is shown to be a platform in which correlated and topological states exist, driven by local lattice relaxations.

Van der Waals heterostructures provide a tunable platform for probing the Andreev bound states responsible for proximity-induced superconductivity, helping to establish a connection between Andreev physics at finite energy and the Josephson effect.

Applying magnetic and electric fields to twisted bilayer graphene creates an electron–hole bilayer that features helical 1D edge modes and fractional quantum Hall states.

Using boron nitride as a substrate for graphene has been suggested as a promising way to reduce the disorder in graphene caused by space fluctuations. It is now shown by scanning tunnelling microscopy that graphene conforms perfectly to boron nitride and the charge fluctuations are minimal compared with the conventionally used substrate, silica. Boron nitride could really be the natural graphene substrate.

Electrons can travel though very pure materials without scattering from defects. In this ballistic regime, magnetic fields can manipulate the electron trajectory. Such magnetic electron focusing is now observed in graphene. Although the effect has previously been seen in metals and semiconductors, it is evident in graphene at much higher temperatures—including room temperature.

It is well known that graphene deposited on hexagonal boron nitride produces moiré patterns in scanning tunnelling microscopy images. The interaction that produces this pattern also produces a commensurate periodic potential that generates a set of Dirac points that are different from those of the graphene lattice itself.

Optical interconnect components based on bilayer MoTe₂ p–n junctions can be directly integrated with silicon photonics

An electrostatically defined p–n junction in monolayer WSe₂ is employed for photodetection, photovoltaic operation and as a light-emitting diode.

The charge carriers in single-layer graphene are effectively massless. In bilayer graphene, they are massive. In trilayer graphene, the two types coexist, which leads to an unusual quantum Hall response in which the Landau levels of massless and massive charge carriers repeatedly cross.

Atomically thin chromium tri-iodide is shown to be a 2D ferromagnetic insulator with an optical response dominated by ligand-field transitions, emitting circularly polarized photoluminescence with a helicity determined by the magnetization direction.

A single field-enhanced terahertz pulse was used to create 1\({T}^{{\prime} }\)-MoTe₂ out of few-layer H-MoTe₂ crystals, providing insights into the ultrafast polymorphic transition dynamics and resolving a long-standing debate over the realization of this transition by high-energy photon irradiation.

An on-chip platform with in situ adjustable interfacial properties, using a microelectromechanical system, provides multi-degree-of-freedom control of two-dimensional materials, including twisting and pressurizing.

We report the experimental realization and room-temperature operation of a low-power (20 pW) moiré synaptic transistor based on an asymmetric bilayer graphene/hexagonal boron nitride moiré heterostructure.

Electronic ferroelectricity is observed in a graphene-based moiré heterostructure, which is explained using a spontaneous interlayer charge-transfer model driven by layer-specific on-site Coulomb repulsion.

Optical chiral induction and spontaneous gyrotropic electronic order are realized in the transition-metal chalcogenide 1T-TiSe₂ by using illumination with mid-infrared circularly polarized light and simultaneous cooling below the critical temperature.

A moiré quasicrystal constructed by twisting three layers of graphene with two different twist angles shows high tunability between a periodic-like regime at low energies and a strongly quasiperiodic regime at higher energies alongside strong interactions and superconductivity.

Superconductivity is reported in magic-angle twisted four-layer and five-layer graphene systems. While they find that all magic-angle graphene systems fit into a unified hierarchy of systems that share a set of flat bands in their electronic band structures, they also report that there is a key distinction between magic-angle twisted bilayer graphene and the other family members, related to the difference in the way the electrons move between the layers in a magnetic field.

Highly tunable moiré superconductivity is observed in magic-angle twisted trilayer graphene, and observations suggest that this superconductor can be tuned close to the crossover to a two-dimensional Bose–Einstein condensate.