EDITORS' SUGGESTION
Nitrogen vacancy (NV) centers in diamond are highly sensitive nanoscale sensors of dc and ac magnetic fields. Vector detection of ac magnetic fields, where both strength and orientation of the applied field is determined, requires at least three NV centers of different orientations by the conventional method. Here, the authors propose and demonstrate a method for vector detection of ac magnetic fields by using NV centers having a single orientation. This method is equally applicable for single NV centers.
Pooja Lamba et al.
Phys. Rev. B 109, 195424 (2024)
EDITORS' SUGGESTION
The subtle interplay between competing degrees of freedom offers an ideal route for the experimental realization of emergent quantum and topological phenomena with exotic quasiparticle excitations in three-dimensional noncentrosymmetric frustrated magnets on a trillium lattice. Here, the authors demonstrate the coexistence of competing magnetic states and short-range spin correlations well above the magnetic phase transition in a frustrated double trillium lattice comprised of Cr ions decorated on a three-dimensional chiral network of corner-shared equilateral triangular motifs.
J. Khatua et al.
Phys. Rev. B 109, 184432 (2024)
EDITORS' SUGGESTION
The authors study here a Su-Schrieffer-Heeger model on a square lattice by auxiliary-field quantum Monte Carlo. A novel approach allows analytical integration over the phonons, considerably reducing autocorrelation times and allowing investigation of new regions of the phase diagram. By varying the strength of the direct hopping at the O(4) symmetric point, they discover novel phases in this textbook model. In particular, for small values of the direct hopping, they observe emergent orthogonal Dirac fermions, with an exotic quantum phase transition akin to deconfined quantum criticality.
Anika Götz, Martin Hohenadler, and Fakher F. Assaad
Phys. Rev. B 109, 195154 (2024)
EDITORS' SUGGESTION
The authors construct here a low-energy model for CeSiI, a new van der Waals (vdW) material that exhibits heavy Fermi liquid behaviour coexisting with magnetic order. Using Abrikosov mean field theory, they observe that the unique geometry of the material facilitates the existence of a nematic heavy Fermi liquid phase as well as a coexistence of heavy Fermi liquid and magnetic order phase. In particular, it is shown that an electric field applied perpendicular to the material consolidates the coexistence phase, demonstrating the high tunability of this new vdW heavy fermion material.
Aayush Vijayvargia and Onur Erten
Phys. Rev. B 109, L201118 (2024)
EDITORS' SUGGESTION
The interplay between real-space topological lattice defects and momentum-space band topology can lead to new topological states. Here, the authors demonstrate that disclinations in acoustic valley-Hall crystals can induce valley-like transport. Using this mechanism, various acoustic topological waveguides with irregular shapes and multiple internal terminations are experimentally realized, providing a novel way for robust free-from waveguiding.
Yin Wang et al.
Phys. Rev. B 109, L180101 (2024)
EDITORS' SUGGESTION
In the 100 years since the Stern-Gerlach experiment, ideas to use inhomogeneous magnetic fields for spintronics have been rare. In the theory here, the authors consider an inverse Stern-Gerlach effect in solid state systems of reduced dimension, in which charge current is produced by an injected carrier spin polarization in a nonuniform field. They find the combination of counter-flowing spin plus spin relaxation leads to interesting dynamics that produce a “Stern-Gerlach” potential, while at the same time reducing the spin transport length.
N. J. Harmon, E. Z. Kurth, D. Coleman, and L. Flanigan
Phys. Rev. B 109, 195423 (2024)
EDITORS' SUGGESTION
The authors explore critical properties of entanglement phase transitions in random tensor networks and monitored quantum circuits with Clifford tensors/gates for on-site Hilbert space dimensions which are powers of a prime number . Exact mappings to replica spin models and characterizations of their symmetry groups predict that all universal properties will depend only on . These predictions are confirmed with extensive numerical simulations. The authors also establish multifractal scaling of the purity, reflected in a continuous spectrum of critical exponents, while the typical exponent is the prefactor of the logarithm in the entanglement entropy.
Yaodong Li, Romain Vasseur, Matthew P. A. Fisher, and Andreas W. W. Ludwig
Phys. Rev. B 109, 174307 (2024)
EDITORS' SUGGESTION
Here, the authors report on the superconducting properties of the ternary noncentrosymmetric superconductor ReNbTa, a new member of the Re-based superconductors that are known for the frequent occurrence of time-reversal symmetry breaking and their complex superconducting ground states. Bulk and transverse field muon spin rotation/relaxation (μSR) measurements confirm moderately coupled, fully gapped superconductivity. However, zero-field μSR measurements indicate the possible presence of spin fluctuation/time-reversal symmetry breaking in the superconducting ground state, suggesting the unconventional superconductivity in ReNbTa.
R. K. Kushwaha et al.
Phys. Rev. B 109, 174518 (2024)
EDITORS' SUGGESTION
Ultrahigh-mobility two-dimensional electron gases show an astonishing robust negative magnetoresistance at zero magnetic field. variation of the electron density enables a deep insight into the nature of this negative magnetoresistance. Here, the authors investigate the temperature-dependent giant negative magnetoresistance (GNMR) as a function of the electron density for several temperatures and currents. They find that the GNMR behavior depends decisively on the electron density. This observation is attributed to a changed disorder potential with electron density.
L. Bockhorn et al.
Phys. Rev. B 109, 205416 (2024)
EDITORS' SUGGESTION
Conformal field theory (CFT) has played a pivotal role in understanding the topological phases of matter represented by many fractional quantum Hall effect (FQHE) trial wave functions. Previous papers have shown how the topological properties of a trial wave function expressible as a CFT correlation function can be related to properties of the corresponding CFT, assuming a field-theoretic generalization of Laughlin’s plasma analogy holds. Here, the authors show how these methods can be extended to understand certain topological properties of parton-type FQHE trial wave functions.
Greg J. Henderson, G. J. Sreejith, and Steven H. Simon
Phys. Rev. B 109, 205128 (2024)
EDITORS' SUGGESTION
Using x-ray resonant magnetic scattering in vector magnetic fields, this work explores the effect of the anisotropic exchange interaction on the magnetic spiral pitch in the cubic chiral magnet CoZnMn. The experimental data reveal up to a 5% variation in the helical pitch within the (001) plane depending on temperature. Furthermore, the results reveal the existence of intrinsic competition between magnetocrystalline and exchange anisotropies in this material, with each favoring different orientations of the helical vector in the ground state.
Victor Ukleev et al.
Phys. Rev. B 109, 184415 (2024)
EDITORS' SUGGESTION
In contrast to dipolar refrigerator magnets, multipolar magnets possess more than just a north pole and a south pole. Using first principles and exact diagonalization calculations, this work establishes transition metal based vacancy-ordered halide double perovskites as new candidates for octupolar magnetism. The authors uncover a non-Kramers doublet ground state in these materials, explain the strong temperature-dependent effective magnetic moment, highlight the breakdown of the classic Kotani plot, and predict hidden octupolar order which may be tested in future experiments.
Koushik Pradhan, Arun Paramekanti, and Tanusri Saha-Dasgupta
Phys. Rev. B 109, 184416 (2024)
EDITORS' SUGGESTION
In hybrid-improper ferroelectrics, two nonpolar structural distortions jointly give rise to a spontaneous electric polarization. In CaMnTiO, this ferroelectric state coexists with antiferromagnetism to yield a new type of multiferroic. Here, the authors show that it is characterized by a pronounced magnetoelectric response of the ferroelectric state to the intrinsic magnetic ordering and to external magnetic fields. Optical second harmonic generation is of particular advantage to this study, as it provides access to the electric polarization with spatial resolution of its domains.
Yannik Zemp et al.
Phys. Rev. B 109, 184417 (2024)
EDITORS' SUGGESTION
Here, the authors make a fundamental theoretical advancement by unifying the theory of optical transitions in semiconductors including direct and phonon-assisted processes. This unification overcomes the fundamental limitation in the textbook theory of phonon-assisted optical absorption that gives unphysical absorption rates for photon energies greater than the direct band gap. They demonstrate the predictive power of their theory by calculating optical absorption and luminescence in standard semiconductors, and they achieve excellent quantitative agreement with the best available experiments. This work brings a paradigm shift in the theory of optical transitions, and opens the pathway for precise calculations of semiconductor optical properties.
Sabyasachi Tiwari, Emmanouil Kioupakis, José Menendez, and Feliciano Giustino
Phys. Rev. B 109, 195127 (2024)