EDITORS' SUGGESTION
Solid-state quantum emitters often suffer from temporal variations of their transition energies, inherited from fluctuations in the host crystal environment. This spectral diffusion (SD) is detrimental to the emitter linewidth but is often challenging to characterize experimentally. The authors show here that, under resonant laser excitation, the statistics of the scattered photons offer multiple signatures of the SD process, making it possible to discriminate between discrete jumps and continuous diffusion, as well as to access relevant parameters of the SD mechanisms.
Aymeric Delteil, Stéphanie Buil, and Jean-Pierre Hermier
Phys. Rev. B 109, 155308 (2024)
EDITORS' SUGGESTION
This paper introduces scalar measures that adequately characterize the non-Hermitian skin effects under open boundary condition. Using these measures, the authors reveal that the topological properties of the non-Hermitian skin effect give a macroscopic enhancement of non-normality under open boundary condition. The topological enhancement of non-normality governs the perturbation sensitivity of the spectra and the anomalous time-evolution dynamics intrinsic to non-Hermiticity. They also show that these measures correctly describe the disorder-induced topological phase transitions of the skin effect.
Yusuke O. Nakai et al.
Phys. Rev. B 109, 144203 (2024)
EDITORS' SUGGESTION
This work establishes a direct connection between the magic-angle effect, originally discovered in two-dimensional twisted bilayer graphene, and the avoided quantum critical point in disordered three-dimensional Weyl and Dirac semimetals. This is achieved through a theoretical study of the interplay of quasiperiodicity and disorder in a model for three-dimensional inversion broken Weyl semimetal. The predictions can be tested in future ultracold atom or circuit quantum electrodynamic experiments.
J. H. Pixley, David A. Huse, and Justin H. Wilson
Phys. Rev. B 109, 165151 (2024)
EDITORS' SUGGESTION
By exploiting naturally occurring charge islands due to twist angle variations in twisted bilayer graphene, the authors measure here how strongly charge carriers interact. They discover negative capacitance contributions, which are indicative of correlation effects near band insulators at full filling on both flat and remote sides, and at integer partial fillings. The correlation strength remains constant across all bands, unaffected by a magnetic field. The reported results point to a possible Wigner crystal phase as the underlying mechanism.
Robin J. Dolleman et al.
Phys. Rev. B 109, 155430 (2024)
EDITORS' SUGGESTION
Using a combination of neutron powder diffraction and SQUID magnetometry, this work explores the impact that hydrogen (deuterium) incorporation has on the magnetic properties of NdGaD (=0, 0.9, and 1.6). The experimental results show that hydrogenation leads to large change in the magnetic order and to a significant decrease in the corresponding transition temperatures. Furthermore, the results suggest that this is related to changes in the electronic structure and the Nd-Nd distances induced by the hydrogenation.
Johan Cedervall et al.
Phys. Rev. B 109, 134434 (2024)
EDITORS' SUGGESTION
Chiral phonons are lattice vibration modes in which the atomic circular motions produce nonzero angular momentum. In monolayer MoS, the authors demonstrate here a chiral phonon mode at ~270 cm that is activated by resonant excitation of the bright exciton. Under an out-of-plane magnetic field, this mode exhibits large Zeeman splitting, which corresponds to an effective magnetic moment of ~2.5 μ. This study will stimulate research on the effective magnetic moments that emerge from the interplay between chiral phonons and the valley degree of freedom.
Chunli Tang et al.
Phys. Rev. B 109, 155426 (2024)
EDITORS' SUGGESTION
Topologically trivial insulators can further be identified as obstructed atomic insulators when the symmetric Wannier functions are centered at positions not occupied by atoms. Here, the authors derive all charge-filling criteria that force a topologically trivial insulator to an obstructed atomic insulator. About one thousand filling-enforced obstructed atomic insulators are found through high-throughput calculations.
Yuanfeng Xu et al.
Phys. Rev. B 109, 165139 (2024)
EDITORS' SUGGESTION
Antimony telluride (SbTe) has garnered significant attention within the condensed matter community, particularly as one of the earliest experimentally recognized topological insulators. However, despite substantial investigation, our understanding of the bulk electronic band structure of SbTe remains incomplete. Here, the authors employ a comprehensive experimental and theoretical approach integrating magneto-optical, optical, magnetotransport and techniques to examine SbTe. Their findings reveal that this material possesses a direct energy band gap at the center of the Brillouin zone, while also exhibiting additional low-energy band extrema in mirror planes.
I. Mohelsky et al.
Phys. Rev. B 109, 165205 (2024)
EDITORS' SUGGESTION
The so-called Remeika phase of the 3–4–13 class of materials is a candidate system for investigating topological electronic phenomena. The authors explore here an antiferromagnetic ordered structure comprising one-dimensional Nd chains connected via the triangular lattice in NdRhSn, which is superimposed on the chiral structure like that in several Remeika phase compounds. The results suggest that simultaneously broken spatial and time-reversal symmetries in this material open an avenue to investigate magnetic interactions mediated by the topological electrons protected by the noncentrosymmetric chiral structure.
Ami Shimoda et al.
Phys. Rev. B 109, 134425 (2024)
EDITORS' SUGGESTION
Altermagnetism is increasingly gaining attention and RuO thin films have been arguably the most popular altermagnetic candidate. However, most publications miss a disturbing fact: direct experiments indicate the absence of any sizable ordered magnetism in stoichiometric bulk samples. Here, the authors confirm, through first-principles calculations, that the bulk samples are indeed far from ordered magnetism, but intrinsic hole doping strongly enhances the tendency to magnetism, suggesting an interesting possibility that the measured thin films may be magnetically different from stoichiometric bulk RuO.
Andriy Smolyanyuk, Igor I. Mazin, Laura Garcia-Gassull, and Roser Valentí
Phys. Rev. B 109, 134424 (2024)
EDITORS' SUGGESTION
To be useful for quantum computation, qubits in an array must remain localized – that is, not “dressed” too much by nearby degrees of freedom. This localization has been previously achieved using disorder. But the authors observe here that a more effective route to localization is with a quasiperiodic patterning of the qubit array Hamiltonian. This paper develops two different perturbation approaches to calculate diagnostics for many-body localization in quasiperiodic superconducting transmon arrays. Perturbing in anharmonicity versus perturbing in hopping strength give complementary information.
Evangelos Varvelis and David P. DiVincenzo
Phys. Rev. B 109, 144201 (2024)
EDITORS' SUGGESTION
Charge density waves (CDW) accompanied by superconductivity (SC) is an enduring topic in the field of condensed matter physics for it involves exotic physical properties and quantum states. This paper presents a competitive relationship between the anisotropic SC and CDW down to the two-dimensional limit in ZrTe, a quasi-one-dimensional material. It reveals an unusual nonmonotonic evolution versus thickness and suggests a complicated superconducting mechanism in this compound.
Xinyu Chen et al.
Phys. Rev. B 109, 144513 (2024)
EDITORS' SUGGESTION
By examining the complex interactions between light and magnetism, this work uncovers the dominant role played by light’s spin angular momentum in magnetic all-optical switching (AOS) using Co/Pt ferromagnetic thin films. The authors use femtosecond vortex beams to demonstrate that the topological charge and orbital angular momentum’s handedness are inconsequential. As a result, this research enhances our comprehension and underscores the pivotal correlation between the angular momentum of light and magnetization dynamics.
Muhammad Waleed Khalid et al.
Phys. Rev. B 109, L140403 (2024)
EDITORS' SUGGESTION
Strong disorder in many-body quantum systems leads to many-body localization (MBL), manifested as long-time memory of the initial state. Spatial regions of anomalously weak disorder, arising due to fluctuations in the disordered potential, may act as ergodic inclusions that seed quantum avalanches and destabilize the MBL. To investigate this mechanism in a controlled setting, the authors plant ergodic inclusions by engineering regions of a weak disorder and compare the system’s time evolution with predictions of the avalanche theory.
Tomasz Szołdra, Piotr Sierant, Maciej Lewenstein, and Jakub Zakrzewski
Phys. Rev. B 109, 134202 (2024)