The valleys in hexagonal two-dimensional systems with broken inversion symmetry carry an intrinsic orbital magnetic moment. Despite this, such systems possess zero net magnetization unless additional symmetries are broken since the contributions from both valleys cancel. A nonzero net magnetization can be induced through applying both uniaxial strain to break the rotational symmetry of the lattice and an in-plane electric field to break time-reversal symmetry owing to the resulting current.

Despite their fundamental importance in dictating the quantum-mechanical properties of a system, ground states of many-body local quantum Hamiltonians form a set of measure zero in the many-body Hilbert space. Hence determining whether a given many-body quantum state is ground-stateable is a challenging task. Here we propose an unsupervised machine learning approach, dubbed Entanglement Clustering ("EntanCl"), to separate out ground-stateable wave functions from those that must be excited-state wave functions using entanglement structure information.

We model the superfluid to Mott insulator transition for a Bose gas on a lattice with two inequivalent sublattices. Using the Gutzwiller ansatz, we produce phase diagrams and provide an understanding of the interplay between superfluidity on each sublattice. We explore how the Mott lobes split and describe the experimental signatures. © 2021 American Physical Society.

In many unconventional superconductors, the presence of a pseudogap - a suppression in the electronic density of states extending above the critical temperature - has been a long-standing mystery. Here, we employ combined in situ electrical transport and angle-resolved photoemission spectroscopy measurements to reveal an unprecedentedly large pseudogap regime in single-layer FeSe/SrTiO3, an interfacial superconductor where incoherent Cooper pairs are initially formed above TΔ≈60 K but where a zero-resistance state is achieved only below T0<30 K.

We investigate the renormalized perturbative triples correction together with the externally corrected coupled-cluster singles and doubles (ecCCSD) method. We use the density matrix renormalization group (DMRG) and heat-bath CI (HCI) as external sources for the ecCCSD equations. The accuracy is assessed for the potential energy surfaces of H2O, N2, and F2. We find that the triples correction significantly improves upon ecCCSD, and we do not see any instability of the renormalized triples with respect to dissociation.

We present a version of the T-moves approach for treating nonlocal pseudopotentials in diffusion Monte Carlo, which has much smaller time-step errors than the existing T-moves approaches, while at the same time preserving desirable features such as the upper-bound property for the energy. In addition, we modify the reweighting factor of the projector used in diffusion Monte Carlo to reduce the time-step error. The latter is applicable not only to pseudopotential calculations but also to all-electron calculations. © 2021 Author(s).

When spin-orbit torques are measured using spin-torque ferromagnetic resonance, two alternative ways of analyzing the results to extract the torque efficiencies - lineshape analysis and analysis of the change in linewidth versus direct current - often give inconsistent results. We identify a source for these inconsistencies.

The tuning catalytic functionality of transition metal dichalcogenides (TMDs) with multi-dimensional defects, such as interfaces (2D), edges (1D), and atomic vacancies (0D), is currently considered a promising strategy for energy applications. The pristine edges and plasma-treated basal planes of various TMDs have been extensively studied for practical hydrogen evolution reaction (HER). Here, we demonstrate active HER on the plasma-treated edges of semimetallic layered tungsten ditellurides (WTe2) using a microcell device.

Spin–orbit torques (SOTs) that arise from materials with large spin–orbit coupling offer a new pathway for energy-efficient and fast magnetic information storage. SOTs in conventional heavy metals and topological insulators are explored extensively, while 5d transition metal oxides, which also host ions with strong spin–orbit coupling, are a relatively new territory in the field of spintronics.