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Abstract The presence of topological flat minibands in moiré materials provides an opportunity to explore the interplay between topology and correlation. In this work, we study moiré minibands in topological insulator films with two hybridized surface states under a moiré superlattice potential created by two-dimensional insulating materials. We show the lowest conduction (highest valence) Kramers’ pair of minibands can be $${{\mathbb{Z}}}_{2}$$ Z 2 non-trivial when the minima (maxima) of moiré potential approximately form a hexagonal lattice with six-fold rotation symmetry. Coulomb interaction can drive the non-trivial Kramers’ minibands into the quantum anomalous Hall state when they are half-filled, which is further stabilized by applying external gate voltages to break inversion. We propose the monolayer Sb2 on top of Sb2Te3 films as a candidate based on first principles calculations. Our work demonstrates the topological insulator based moiré heterostructure as a potential platform for studying interacting topological phases.

We investigate the phase diagram at the boundary of an infinite two-dimensional cluster state subject to bulk measurements using tensor network methods. The state is subjected to uniform measurements M=cosθZ+sinθX on the lower boundary qubits and in all bulk qubits. Our results show that the boundary of the system exhibits volume-law entanglement at the measurement angle θ=π/2 and area-law entanglement for any θ

The responses of anammox consortia to typical antibiotics sulfadiazine (SDZ) and chlortetracycline (CTC) were evaluated on the aspects of general performance, microbial activity, diversity and abundance of antibiotic resistance genes (ARGs), and microbial host of ARGs in anammox system. Results showed the anammox consortia had a stable performance and great resistance to 10 mg/L of SDZ, while 1 mg/L of CTC induced an unrecoverable inhibitory influence on nitrogen removal performance and anammox activity without any special treatment. The absolute abundances of anammox functional genes (nirS, hzsA and hdh) were stimulated by the acclimation to SDZ stress, however, they were much lower than the initial levels under CTC stress. In anammox consortia, ARGs comprised 18 types (94 subtypes) derived from over 20 genera. Strikingly, the anammox bacteria (AnAOB) “Ca. Brocadia” occupied 46.81% of the SDZ resistance genes (sul1 and sul2) and 38.63% of CTC resistance genes (tetX, tetG and rpsJ), and thus were identified as the dominant antibiotic resistance bacteria (ARB). Therefore, harboring the corresponding ARGs by AnAOB could be the primary protective mechanism to interpret the resistance of anammox consortia to antibiotics stress. Meanwhile, co-occurring of ARGs in anammox consortia suggested the synergistic cooperation of different ARGs could be an essential strategy to alleviate the SDZ and CTC stress. The present study proposed a new interpretation of possible mechanism that cause antibiotic resistance of anammox consortia.

A correlated insulator has recently been observed in twisted bilayer WSe2 moiré superlattices. Here, Bi and Fu present a theory and predict the insulating state to be an excitonic density wave as well as a spin-valley superfluid, which can be tested by optical pump-probe experiments.

Porcine deltacoronavirus (PDCoV) is a novel enteric coronavirus and is becoming one of the major causative agents of diarrhea in pig herds in recent years. To date, there are no commercial vaccines or antiviral pharmaceutical agents available to control PDCoV infection. Therefore, developing a reliable strategy against PDCoV is urgently needed. In this study, to observe the antiviral activity of RNA interference (RNAi), four short hairpin RNAs (shRNAs) specific to the nucleocapsid (N) gene of PDCoV were designed and tested in vitro. Of these, a double-shRNA-expression vector, designated as pSil-double-shRNA-N1, was the most effectively expressed, and the inhibition of PDCoV replication was then further evaluated in neonatal piglets. Our preliminary results reveal that plasmid-based double-shRNA-expression targeting the N gene of PDCoV can significantly protect LLC-PK1 cells and piglets from pathological lesions induced by PDCoV. Our study could benefit the investigation of the specific functions of viral genes related to PDCoV infection and offer a possible methodology of RNAi-based therapeutics for PDCoV infection.

Copper tin sulfides (CTSs) have widely been investigated as electrode materials for supercapacitors owing to their high theoretical pseudocapacitances. However, the poor intrinsic conductivity and volume change during redox reactions hindered their electrochemical performances and broad applications. In this study, carbon quantum dots (CQDs) were employed to modify CTSs. The structures and morphologies of obtained materials were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD revealed CTSs were composed of Cu2SnS3 and Cu4SnS4, and TEM suggested the decoration of CQDs on the surface of CTSs. With the decoration of CQDs, CTSs@CQDs showed a remarkable specific capacitance of 856 F·g−1 at 2 mV·s−1 and a high rate capability of 474 F·g−1 at 50 mV·s−1, which were superior to those of CTSs (851 F·g−1 at 2 mV·s−1 and 192 F·g−1 at 50 mV·s−1, respectively). This was mainly ascribed to incorporation of carbon quantum dots, which improved the electrical conductivity and alleviated volume change of CTSs during charge/discharge processes.

Fe-dependent nitrate reduction by anammox consortia could serve as a valuable autotrophic denitrification process for wastewater treatment. However, influences of temperature, pH, and Fe/NO3-N ratio on this biochemical process have not been studied. The present study investigated individual and interactive effects of aforementioned parameters on nitrate removal performance and bioactivity of anammox consortia via a series of batch assays. Enzymes activity of nitrate reductase (NAR) and hydrazine dehydrogenase (HDH) of anammox consortia had high consistency with nitrogen removal performance and significantly depended on temperature and Fe/NO3-N ratio, while the narG and hdh genes expression were drastically depressed by extreme temperature. Models developed by response surface methodology (RSM) showed the significance of individual parameter followed by Fe/NO3-N ratio > temperature > pH, while combined effects of temperature versus Fe/NO3-N ratio exerted the most significant impacts. The pH in range of 4.0–8.0 had less influence. The optimum condition for nitrate removal efficiency (NRE) > 90% and total nitrogen removal efficiency (TNRE) > 75% was 4.0–7.4 for pH, 25.5–30.0 °C for temperature, and 31–48 for Fe/NO3-N molar ratio. The maximum NRE and TNRE could be 98.68% and 79.42%, respectively, under the condition of pH = 4.00, temperature = 28.5 °C and Fe/NO3-N ratio = 37.4. The models showed good dependability for simulation nitrogen removal performance by anammox in the real semiconductor wastewater.

Continuous phase transitions associated with the onset of a spontaneously broken symmetry are thought to be successfully described by the Landau-Ginzburg-Wilson-Fisher theory of fluctuating order parameters. In this work, we show that such transitions can admit new universality classes which cannot be understood in terms of a theory of order parameter fluctuations. We explicitly demonstrate continuous time reversal symmetry breaking quantum phase transitions of 3+1-D bosonic systems described by critical theories expressed in terms of a deconfined gauge theory with massless Dirac fermions instead of the fluctuating Ising order parameter. We dub such phase transitions “Landau transitions beyond Landau description” (LBL). A key feature of our examples is that the stability of the LBL fixed points requires a crucial global symmetry, which is nonanomalous, unbroken, and renders no symmetry protected topological phase throughout the phase diagram. Despite this, there are elementary critical fluctuations of the phase transition that transform projectively under this symmetry group. We also construct examples of other novel quantum critical phenomena, notably a continuous Landau-forbidden deconfined critical point between two Landau-allowed phases in 3+1-D.

Paramagnetic spin systems with spontaneously broken spatial symmetries, such as valence bond solid phases, can host topological defects carrying nontrivial quantum numbers, which enables the paradigm of deconfined quantum criticality. In this work, we study the properties of topological defects in valence plaquette solid (VPS) phases on square and cubic lattices. We show that the defects of the VPS order parameter, in addition to possessing nontrivial quantum numbers, have fracton mobility constraints deep in the VPS phase, which has been overlooked previously. The spinon inside a single vortex cannot move freely in any direction, while a dipolar pair of vortices with spinon pairs can only move perpendicularly to its dipole moment. These mobility constraints, while they persist, can potentially inhibit the condensation of vortices and preclude a continuous transition from the VPS to the Néel antiferromagnet. Instead, the VPS melting transition can be driven by proliferation of spinon dipoles. For example, we argue that a two-dimensional VPS can melt into a stable gapless phase in the form of an algebraic bond liquid with algebraic correlations and long-range entanglement. Such a bond liquid phase yields a concrete example of the elusive two-dimensional Bose metal with symmetry fractionalization. We also study the three-dimensional valence plaquette and valence cube ordered phase, and demonstrate that the topological defects therein also have fractonic dynamics. Possible nearby phases after melting the valence plaquettes or cubes are also discussed.

The experimental observation of superconductivity in doped semimetals and semiconductors, where the Fermi energy is comparable to or smaller than the characteristic phonon frequencies, is not captured by the conventional theory. In this paper, we propose a mechanism for superconductivity in ultralow-density three-dimensional Dirac materials based on the proximity to a ferroelectric quantum critical point. We derive a low-energy theory that takes into account both the strong Coulomb interaction and the direct coupling between the electrons and the soft phonon modes. We show that the Coulomb repulsion is strongly screened by the lattice polarization near the critical point even in the case of a vanishing carrier density. Using a renormalization group analysis, we demonstrate that the effective electron-electron interaction is dominantly mediated by the transverse phonon mode. We find that the system generically flows towards strong electron-phonon coupling. Hence, we propose a new mechanism to simultaneously produce an attractive interaction and suppress strong Coulomb repulsion, which does not require retardation. For comparison, we perform the same analysis for covalent crystals, where lattice polarization is negligible. We obtain qualitatively similar results, though the screening of the Coulomb repulsion is much weaker. We then apply our results to study superconductivity in the low-density limit. We find a strong enhancement of the transition temperature upon approaching the quantum critical point. Finally, we also discuss scenarios to realize a topological p-wave superconducting state in covalent crystals close to the critical point.

Continuous quantum phase transitions beyond the conventional paradigm of fluctuations of a symmetry-breaking order parameter are challenging for theory. These phase transitions often involve emergent deconfined gauge fields at the critical points as demonstrated in phase transitions between different broken-symmetry states of 2+1-dimensional quantum magnets, as well as those between symmetry-protected topological (SPT) phases. In this paper, we present several examples of deconfined quantum critical points between SPT phases in 3+1-D for both bosonic and fermionic systems. These critical theories can be formulated as non-Abelian gauge theories either in the infrared-free regime or in the conformal window when they flow to the Banks-Zaks fixed points. We explicitly demonstrate several interesting quantum critical phenomena. We describe situations in which the same phase transition allows for multiple universality classes controlled by distinct fixed points. We exhibit the possibility—which we dub “unnecessary quantum critical points”—of stable generic continuous phase transitions within the same phase. We present examples of interaction-driven, band-theory-forbidden, continuous phase transitions between two distinct band insulators. The understanding we develop leads us to suggest an interesting possible 3+1-D field theory duality between SU(2) gauge theory coupled to one massless adjoint Dirac fermion and the theory of a single massless Dirac fermion augmented by a decoupled topological field theory.

In this study, ternary Cu2SnS3 (CTS) nanostructure materials with high crystallinity were successfully prepared via a facile solvothermal method, which was followed by high-temperature treatment. The morphology of the as-synthesized samples is uniform flower-like spheres, with these spheres consisting of hierarchical nanosheets and possessing network features. Sodium storage measurements demonstrate that the annealed CTS electrodes have high initial reversible capacity (447.7 mAh·g−1 at a current density of 100 mA·g−1), good capacity retention (200.6 mAh·g−1 after 50 cycles at a current density of 100 mA·g−1) and considerable rate capability because of their high crystallinity and unique morphology. Such good performances indicate that the high crystallinity CTS is a promising anode material for sodium ion batteries.

In this paper we construct bosonic short range entangled (SRE) states in all spatial dimensions by coupling a ${{\mathbb{Z}}}_{2}$ gauge field to fermionic SRE states with the same symmetries , and driving the ${{\mathbb{Z}}}_{2}$ gauge field to its confined phase. We demonstrate that this approach allows us to construct many examples of bosonic SRE states, and we demonstrate that the previous descriptions of bosonic SRE states such as the semiclassical nonlinear sigma model field theory and the Chern–Simons field theory can all be derived using the fermionic SRE states.

We investigate the moiré band structures and the strong correlation effects in twisted bilayer MoTe2 for a wide range of twist angles, employing a combination of various techniques. Using large-scale first-principles calculations, we pinpoint realistic continuum modeling parameters, subsequently deriving the maximally localized Wannier functions for the top three moiré bands. Simplifying our model with reasonable assumptions, we obtain a minimal two-band model, encompassing Coulomb repulsion, correlated hopping, and spin exchange. Our minimal interaction models pave the way for further exploration of the rich many-body physics in twisted MoTe2. Furthermore, we explore the phase diagrams of the system through Hartree-Fock approximation and exact diagonalization (ED). Our two-band ED analysis underscores significant band-mixing effects in this system, which enlarge the optimal twist angle for fractional quantum anomalous Hall states. [ABSTRACT FROM AUTHOR]