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The strength of the interaction between the spin state and orbital motion of electrons in a semiconducting quantum dot can be controlled by electrical gates.

Many discrepancies exist to question the nature of the candidate topological Kondo insulator, SmB₆. Here, Jiao et al. observe in-gap states on well characterized (001) surfaces of SmB₆, indicating a suppression of the Kondo effect at surface, which reconciles current discrepancies on this compound.

The authors demonstrate a nanoscale particle-exchange heat engine using a diradical molecule coupled to superconducting electrodes. By driving a phase transition into the Yu-Shiba-Rusinov regime, they achieve a fivefold boost in thermoelectric power, enabling advances in cryogenic heat recovery and quantum cooling.

The Planckian metal is a special case of a strange metal, in which the linear-in-temperature scattering rate reaches a universal limit. Here the authors study this state in a heavy-fermion superconductor in magnetic field and propose a microscopic mechanical based on quantum criticality of the Kondo hybridization.

Recent theory has shown that the non-equilibrium response of a Kondo model can be described by the Fermi liquid theory with three-body correlations. Here, the authors experimentally measure such correlations in the nonlinear conductance of a Kondo-correlated quantum dot.

Quantum spin liquids are a state of magnetic order that, in analogy with ordinary liquids, is characterized by fluctuating, disordered spins. By means of specific heat measurements, the frustrated Kondo system Pr₂Ir₂O₇ is shown to undergo a transition to such a state in zero magnetic field.

Molecular magnets are molecules with an inherent non-zero spin that can exhibit magnetic ordering. Here, the authors show that such molecules can change the many-body ground state of nonmagnetic metals at a functional scale with magnetic phthalocyanines.

Near-term quantum computers hold many promises but remain limited to a moderate number of qubits. This Article presents a pathway for modeling correlated materials with a reduced number of qubits, bringing quantum computing to materials modeling.

Despite the theoretical prediction of spinaron quasiparticles in artificial nanostructures, experimental evidence has not yet been seen. Now it has been observed in a hybrid system comprising Co atoms on a Cu(111) surface.

The Dzyaloshinskii-Moriya exchange interaction arises in magnetic systems with broken inversion symmetry and promotes chiral magnetic order which may be exploited in spintronic devices. Here, the authors demonstrate how such an interaction between magnetic atoms on a metallic surface may be tuned by their separation.

Complex oxide devices provide a platform for studying and making use of strongly correlated electronic behavior. Here the authors present a LaAlO₃/SrTiO₃ quantum dot and show that its transport behavior is consistent with the presence of attractive electron interactions and the charge Kondo effect.

The authors study microstructured UTe₂ by high-field transport, focusing on the field-reinforced superconducting phase. They reveal a highly-directional vortex pinning force typical of quasi-2D superconductors, indicating a vortex lock-in state and consistent with a change of order parameter from the low-field superconducting phase.

A tunable concentration of localized magnetic impurities is inserted into a metal from a molecular monolayer, which allows many-body phenomena in magnetic impurity–host systems to be studied at unprecedented impurity concentrations.

Clathrate materials have been the subject of intense investigation because of their beneficial properties, in particular their low thermal conductivities. Now, improved thermopower at high temperatures arising from strong electron correlation effects has been achieved in a type-I clathrate containing cerium guest atoms.

Transition-metal atoms deposited on metal surfaces exhibit zero bias anomalies, which have been detected by scanning tunnelling spectroscopy and are commonly attributed to Kondo resonances. Here the authors explain the zero-bias anomalies in terms of gapped spin-excitations in contrast to Kondo resonances, which reproduce well the experiments.

The rare-earth superconductor PrTr₂Al₂₀ (Tr = Ti, V) possesses quadrupolar and octupolar but no magnetic dipolar moments. Here, the authors suggest an intimate link between the quadrupolar order parameter and the superconducting pairing in this material.

Under chemical pressure, two phase transitions that were seemingly linked become detached in YbRh₂Si₂, thereby clarifying a long-standing mystery in the heavy-electron metals. Moreover, a new quantum phase appears under negative pressure.

Electrons in f orbitals can create localized states that interact strongly and drive strange metal and critical behaviour via the Kondo mechanism. Now a mechanism of geometric frustration enables similar phenomena with d electrons.

Building on ideas from quantum information science and on recent experimental advances, the use of ultracold alkaline-earth atoms in optical lattices as quantum simulators of many-body phenomena is proposed. The corresponding models possess a high degree of symmetry and may provide fundamental insights into strongly correlated systems.

The interactions of quasiparticles can be described by renormalizing their masses, such that some materials have a vanishingly small effective mass, whereas others have a very high effective mass. The observation by Vyalikh and colleagues of both extremes occurring on the surface and interior of the same material offers a new view of many-body interactions.

Information technology based on few atom magnets requires both long spin-energy relaxation times and flexible inter-bit coupling. Here, the authors show routes to manipulate information in three-atom clusters strongly coupled to substrate electrons by exploiting Dzyaloshinskii–Moriya interactions.

The impact of local magnetic impurities on superconducting order parameter remains largely unexplored. Here, the authors visualize the effect of different magnetic perturbations on a superconductor, unveiling a rich correlation of the interplay between quantum spins and superconductivity in different spectroscopic regimes.

Charge-neutral excitations have been proposed to explain metal-like thermal transport in Kondo insulators. Here, the authors demonstrate the coupling between charge-neutral excitations and spin degrees of freedom in a Kondo insulator YbIr₃Si₇, which puts restrictions on current theories.

Open-shell nanographenes are used to fabricate length-controlled antiferromagnetic spin-1/2 Heisenberg chains. It is revealed that the spin excitation spectra evolve from gapped to gapless following a power-law dependence on chain length, along with the visualization of the standing waves of confined single spinons.

Heavy-fermion materials have unusual electronic behavior due to a dual localized-itinerant character of 4f electrons. Here, by studying divalent EuRh₂Si₂, the authors gain insight into the electronic states of the trivalent heavy fermion system YbRh₂Si₂ and show that it experimentally demonstrates Luttinger’s theorem.

The identification of the magnetic-fluctuation mode at a quantum phase transition of the archetypical heavy-fermion compound Ce_1−xLa_xRu₂Si₂ indicates that quantum criticality in this system is governed by collective antiferromagnetic behaviour, rather than by local magnetic moments as has been suggested.

This article reviews emergent nanoscale phenomena related to nanoscale contacts, which can have a great impact on the results of nanoelectronic experiments.

The nature of quantum criticality in intermetallic f-electron compounds exhibiting valence fluctuations is not well understood. Here, using a combination of experimental techniques, the authors attribute quantum criticality in YbAlB₄ to the anisotropic hybridization between the conduction and f-electrons.

The insertion of a few unit-cell-thick EuTiO₃ layers at the interface between LaAlO₃ and SrTiO₃ leads to the formation of an electric-field-tunable quasi-two-dimensional electron system where ferromagnetism and superconductivity coexist.

Although LaAlO₃ and SrTiO₃ are both insulators, when they are brought together at a (100) interface, a highly conducting two-dimensional electron gas forms between them. Annandi et al.show that this also happens at a (110) interface, counter to expectations that it should not.

The spin Hall effect and its inverse allow conversion between charge and spin currents in both magnetic and nonmagnetic materials. Weiet al.observe an anomaly in the temperature dependence of the inverse spin Hall effect, which suggests that it can also be used as a sensor for very small magnetic moments.

The realization of the anomalous Hall effect in high-mobility two dimensional electron systems has so far remained elusive. Here, the authors observe its emergence in MgZnO/ZnO heterostructures and attribute it to skew scattering of electrons by localized paramagnetic centres.

Spin caloritronics explores the interplay among spin, heat and charges in condensed matter towards new thermoelectric functionalities and applications. This Review provides an analysis of the role of spin in enhancing charge-based thermoelectricity, magneto-thermoelectricity and thermospin effects.

Pr₂Ir₂O₇ is a candidate for a metallic spin liquid with a quantum critical point; however, the exact nature of its ground state and quantum criticality is unknown. Here, the authors report strong deviations from dipolar spin-ice ground state and find normal electronic behavior near quantum criticality.

The heavy-fermion compound YbRh₂Si₂ possesses a quantum critical point, at which the standard theory of electron behaviour in metals is expected to break down; such anomalous behaviour has now been observed.

Samarium hexahoride is argued to be a topological Kondo insulator, but this claim remains under debate. Here, Hlawenka et al. provide a topologically trivial explanation for the conducting states at the (100) surface of samarium hexaboride; an explanation based on Rashba splitting and a surface shift of the Kondo resonance.

A quantum critical point associated with a carbon nanotube quantum dot that is in contact with dissipative leads exhibits striking non-Fermi-liquid properties and anomalous scaling. The dissipative environment enables the comparison of the system under thermal- and non-equilibrium conditions.

The coupling of spin and orbital motion of electrons in carbon nanotubes has been demonstrated before, but a study now shows that the strength and sign of the spin–orbit coupling can be tuned by a gate voltage, and that, importantly for future applications, the effect survives in the presence of disorder.

Thermal-expansion measurements of CeCu_6−xAu_x reveal the thermodynamic landscape of this material’s entropy, offering insights into the behaviour of quantum critical fluctuations as the system approaches its quantum critical point.

Recently, rich condensed matter physics has emerged from the interplay between band topology and magnetic order. Here, the authors characterize the magnetic Weyl semimetal CeAlGe and find evidence for the role of Weyl fermions in stabilizing the magnetic order above the local transition temperature.

Nuclear magnetic resonance measurements reveal two separate relaxation channels—one associated with a Fermi liquid state and the other with a non-Fermi liquid state—coexisting near a quantum phase transition in YbRh₂Si₂.

Thermoelectric performances depend on phonon and electron transport. Here, Takahashi et al. show that the large Seebeck coefficient observed in high-purity single-crystal FeSb₂ is due to the phonon-drag effect and to the high effective mass of delectrons interacting with quasi-ballistic phonons.