From fractional quantum anomalous Hall smectics to polar smectic metals: nontrivial interplay between electronic liquid crystal order and topological order in correlated topological flat bands.

Symmetry-breaking orders can not only compete with each other, but also be intertwined, and the intertwined topological and symmetry-breaking orders make the situation more intriguing. This work examines the archetypal correlated flat band model on a checkerboard lattice at fillingν=2/3and we find that the unique interplay between smectic charge order and topological order gives rise to two novel quantum states. As the interaction strength increases, the system first transitions from a Fermi liquid (FL) into FQAH smectic (FQAHS) state, where the topological order coexists cooperatively with smectic charge order with enlarged ground-state degeneracy and interestingly, the Hall conductivity isσxy=ν=2/3, different from the band-folding or doping scenarios. Further increasing the interaction strength, the system undergoes another quantum phase transition and evolves into a polar smectic metal (PSM) state. This emergent PSM is an anisotropic non-Fermi liquid, whose interstripe tunneling is irrelevant while it is metallic inside each stripe. Different from the FQAHS and conventional smectic orders, this PSM spontaneously breaks the two-fold rotational symmetry, resulting in a nonzero electric dipole moment and ferroelectric order. In addition to the exotic ground states, large-scale numerical simulations are also used to study low-energy excitations and thermodynamic characteristics. We find that the onset temperature of the incompressible FQAHS state, which also coincides with the onset of non-polar smectic order, is dictated by the magneto-roton modes. Above this onset temperature, the PSM state exists at an intermediate-temperature regime. Although theT = 0 quantum phase transition between PSM and FQAHS is first order, the thermal FQAHS-PSM transition could be continuous. We expect the features of the exotic states and thermal phase transitions could be accessed in future experiments.

Phases of (2+1)D SO(5) Nonlinear Sigma Model with a Topological Term on a Sphere: Multicritical Point and Disorder Phase.

Novel critical phenomena beyond the Landau-Ginzburg-Wilson paradigm have been long sought after. Among many candidate scenarios, the deconfined quantum critical point (DQCP) constitutes the most fascinating one, and its lattice model realization has been debated over the past two decades. Here we apply the spherical Landau level regularization upon the exact (2+1)D SO(5) nonlinear sigma model with a topological term to study the potential DQCP therein. We perform a density matrix renormalization group (DMRG) simulation with SU(2)_{spin}×U(1)_{charge}×U(1)_{angular-momentum} symmetries explicitly implemented. Using crossing point analysis for the critical properties of the DMRG data, accompanied by quantum Monte Carlo simulations, we accurately obtain the comprehensive phase diagram of the model and find various novel quantum phases, including Néel, ferromagnet (FM), valence bond solid (VBS), valley polarized (VP) states and a gapless quantum disordered phase occupying an extended area of the phase diagram. The VBS-disorder and Néel-disorder transitions are continuous with non-Wilson-Fisher exponents. Our results show the VBS and Néel states are separated by either a weakly first-order transition or the disordered region with a multicritical point in between, thus opening up more interesting questions on the two-decade long debate on the nature of the DQCP.

Thermodynamic Response and Neutral Excitations in Integer and Fractional Quantum Anomalous Hall States Emerging from Correlated Flat Bands.

Integer and fractional Chern insulators have been extensively explored in correlated flat band models. Recently, the prediction and experimental observation of fractional quantum anomalous Hall (FQAH) states with spontaneous time-reversal symmetry breaking have garnered attention. While the thermodynamics of integer quantum anomalous Hall (IQAH) states have been systematically studied, our theoretical knowledge on thermodynamic properties of FQAH states has been severely limited. Here, we delve into the general thermodynamic response and collective excitations of both IQAH and FQAH states within the paradigmatic flat Chern-band model with remote band considered. Our key findings include (i) in both ν=1 IQAH and ν=1/3 FQAH states, even without spin fluctuations, the charge-neutral collective excitations would lower the onset temperature of these topological states, to a value significantly smaller than the charge gap, due to band mixing and multiparticle scattering; (ii) by employing large-scale thermodynamic simulations in FQAH states in the presence of strong interband mixing between C=±1 bands, we find that the lowest collective excitations manifest as the zero-momentum excitons in the IQAH state, whereas in the FQAH state, they take the form of magnetorotons with finite momentum; (iii) the unique charge oscillations in FQAH states are exhibited with distinct experimental signatures, which we propose to detect in future experiments.

Effects of Voice Pitch on Social Perceptions Vary With Relational Mobility and Homicide Rate.

Fundamental frequency ( fo) is the most perceptually salient vocal acoustic parameter, yet little is known about how its perceptual influence varies across societies. We examined how fo affects key social perceptions and how socioecological variables modulate these effects in 2,647 adult listeners sampled from 44 locations across 22 nations. Low male fo increased men's perceptions of formidability and prestige, especially in societies with higher homicide rates and greater relational mobility in which male intrasexual competition may be more intense and rapid identification of high-status competitors may be exigent. High female fo increased women's perceptions of flirtatiousness where relational mobility was lower and threats to mating relationships may be greater. These results indicate that the influence of fo on social perceptions depends on socioecological variables, including those related to competition for status and mates.

Attachment security, environmental adversity, and fast life history behavioral profiles in human adolescents.

One species-general life history (LH) principle posits that challenging childhood environments are coupled with a fast or faster LH strategy and associated behaviors, while secure and stable childhood environments foster behaviors conducive to a slow or slower LH strategy. This coupling between environments and LH strategies is based on the assumption that individuals' internal traits and states are independent of their external surroundings. In reality, individuals respond to external environmental conditions in alignment with their intrinsic vitality, encompassing both physical and mental states. The present study investigated attachment as an internal mental state, examining its role in mediating and moderating the association between external environmental adversity and fast LH strategies. A sample of 1169 adolescents (51% girls) from 9 countries was tracked over 10 years, starting from age 8. The results confirm both mediation and moderation and, for moderation, secure attachment nullified and insecure attachment maintained the environment-LH coupling. These findings suggest that attachment could act as an internal regulator, disrupting the contingent coupling between environmental adversity and a faster pace of life, consequently decelerating human LH.

Three reasons why parental burnout is more prevalent in individualistic countries: a mediation study in 36 countries.

PURPOSE: The prevalence of parental burnout, a condition that has severe consequences for both parents and children, varies dramatically across countries and is highest in Western countries characterized by high individualism. METHOD: In this study, we examined the mediators of the relationship between individualism measured at the country level and parental burnout measured at the individual level in 36 countries (16,059 parents). RESULTS: The results revealed three mediating mechanisms, that is, self-discrepancies between socially prescribed and actual parental selves, high agency and self-directed socialization goals, and low parental task sharing, by which individualism leads to an increased risk of burnout among parents. CONCLUSION: The results confirm that the three mediators under consideration are all involved, and that mediation was higher for self-discrepancies between socially prescribed and actual parental selves, then parental task sharing, and lastly self-directed socialization goals. The results provide some important indications of how to prevent parental burnout at the societal level in Western countries.

Family obligation in Chinese adolescents: Consequences and parental antecedents.

Adolescents' family obligation is a cultural strength that shows enduring prevalence in China. Given that the meaning of family obligation has undergone rapid changes in recent decades, it is crucial to examine the role of family obligation in adolescent adjustment in contemporary China. More importantly, although past research has investigated the consequences of family obligation on adolescents' adjustment, little is known about the antecedents of Chinese adolescents' family obligation. Using a two-wave longitudinal sample of 450 Chinese adolescents (mean age = 13.78 years, SD = .71 years; 49% female) and their parents, the current research explored two questions. First, this study examined the role of family obligation in adolescents' academic achievement, externalizing problems, and internalizing problems over early adolescence. Second, this study explored the role of parents in predicting Chinese adolescents' family obligation, specifically whether parental expectations or parental acceptance was predictive of adolescents' family obligation over time. Third, this study investigated whether family obligation is an underlying mechanism between parenting and Chinese adolescents' adjustment. Results showed that Chinese adolescents' family obligation was longitudinally associated with increased academic achievement and reduced externalizing problems. Moreover, perceived parental acceptance, but not parental expectations, was longitudinally associated with Chinese adolescents' greater family obligation. Notably, family obligation mediated the longitudinal effect of parental acceptance on Chinese adolescents' externalizing problems. By studying both the consequences and antecedents of Chinese adolescents' family obligation, this study helps provide a comprehensive understanding of this cultural strength.

Cultural values, parenting, and child adjustment in China.

To examine whether parents' cultural values are related to parenting practices and children's behavioural adjustment, mothers, fathers and children (N = 218) from two cities in China (Jinan and Shanghai) were interviewed when children were, on average, 10 years old. Mothers and fathers reported their endorsement of cultural values (individualism, collectivism, conformity), which were used to separately predict warmth and family obligation expectations reported by each parent, as well as children's report of parental psychological control, rule setting, knowledge solicitation and perceived family obligation expectations. Cross-informant (parents and child) composites of internalising and externalising behaviours were also obtained. The results showed that maternal individualism positively predicted parents' knowledge solicitation. Parental collectivism positively predicted their own warmth and family obligation expectations. Mothers' conformity positively predicted mothers' family obligation expectations, paternal warmth and children's perception of family obligation, whereas fathers' conformity only positively predicted fathers' family obligation expectations. These effects were largely consistent across regional subsamples, although mothers in Jinan were more collectivistic than mothers in Shanghai, and parents in Shanghai adopted less psychological control and more knowledge solicitation in parenting.

Amperometric Identification of Single Exosomes and Their Dopamine Contents Secreted by Living Cells.

Dopamine (DA) is an important neurotransmitter, which not only participates in the regulation of neural processes but also plays critical roles in tumor progression and immunity. However, direct identification of DA-containing exosomes, as well as quantification of DA in single vesicles, is still challenging. Here, we report a nanopipette-assisted method to detect single exosomes and their dopamine contents via amperometric measurement. The resistive-pulse current measured can simultaneously provide accurate information of vesicle translocation and DA contents in single exosomes. Accordingly, DA-containing exosomes secreted from HeLa and PC12 cells under different treatment modes successfully detected the DA encapsulation efficiency and the amount of exosome secretion that distinguish between cell types. Furthermore, a custom machine learning model was constructed to classify the exosome signals from different sources, with an accuracy of more than 99%. Our strategy offers a useful tool for investigating single exosomes and their DA contents, which facilitates the analysis of DA-containing exosomes derived from other untreated or stimulated cells and may open up a new insight to the research of DA biology.

Thermodynamic Characteristic for a Correlated Flat-Band System with a Quantum Anomalous Hall Ground State.

While the ground-state phase diagram of the correlated flat-band systems has been intensively investigated, the dynamic and thermodynamic properties of such lattice models are less explored, but it is the latter which is most relevant to the experimental probes (transport, quantum capacitance, and spectroscopy) of the quantum moiré materials such as twisted bilayer graphene. Here we show, by means of momentum-space quantum Monte Carlo and exact diagonalization, in chiral limit there exists a unique thermodynamic characteristic for the correlated flat-band model with interaction-driven quantum anomalous Hall (QAH) ground state, namely, the transition from the QAH insulator to the metallic state takes place at a much lower temperature compared with the zero-temperature single-particle gap generated by the long-range Coulomb interaction. Such low transition temperature comes from the proliferation of excitonic particle-hole excitations, which transfers the electrons across the gap between different topological bands to restore the broken time-reversal symmetry and gives rise to a pronounced enhancement in the charge compressibility. Future experiments, to verify such generic thermodynamic characteristics, are proposed.

Tangent Space Approach for Thermal Tensor Network Simulations of the 2D Hubbard Model.

Accurate simulations of the two-dimensional (2D) Hubbard model constitute one of the most challenging problems in condensed matter and quantum physics. Here we develop a tangent space tensor renormalization group (tanTRG) approach for the calculations of the 2D Hubbard model at finite temperature. An optimal evolution of the density operator is achieved in tanTRG with a mild O(D^{3}) complexity, where the bond dimension D controls the accuracy. With the tanTRG approach we boost the low-temperature calculations of large-scale 2D Hubbard systems on up to a width-8 cylinder and 10×10 square lattice. For the half-filled Hubbard model, the obtained results are in excellent agreement with those of determinant quantum Monte Carlo (DQMC). Moreover, tanTRG can be used to explore the low-temperature, finite-doping regime inaccessible for DQMC. The calculated charge compressibility and Matsubara Green's function are found to reflect the strange metal and pseudogap behaviors, respectively. The superconductive pairing susceptibility is computed down to a low temperature of approximately 1/24 of the hopping energy, where we find d-wave pairing responses are most significant near the optimal doping. Equipped with the tangent-space technique, tanTRG constitutes a well-controlled, highly efficient and accurate tensor network method for strongly correlated 2D lattice models at finite temperature.

Fermion Disorder Operator at Gross-Neveu and Deconfined Quantum Criticalities.

The fermion disorder operator has been shown to reveal the entanglement information in 1D Luttinger liquids and 2D free and interacting Fermi and non-Fermi liquids emerging at quantum critical points (QCPs) [W. Jiang et al., arXiv:2209.07103]. Here we study, by means of large-scale quantum Monte Carlo simulation, the scaling behavior of the disorder operator in correlated Dirac systems. We first demonstrate the logarithmic scaling behavior of the disorder operator at the Gross-Neveu (GN) chiral Ising and Heisenberg QCPs, where consistent conformal field theory (CFT) content of the GN-QCP in its coefficient is found. Then we study a 2D monopole-free deconfined quantum critical point (DQCP) realized between a quantum-spin Hall insulator and a superconductor. Our data point to negative values of the logarithmic coefficients such that the DQCP does not correspond to a unitary CFT. Density matrix renormalization group calculations of the disorder operator on a 1D DQCP model also detect emergent continuous symmetries.

Carbon dots with hydrogen bond-controlled aggregation behavior.

Here, hydrophilic carbon dots (H-CDs) are prepared by a facile room temperature method. The strength of hydrogen bonds can be controlled by introducing proton and aprotic solvents, respectively, so as to realize the tunable aggregation state of H-CDs. Because of the ultrasensitive response to dimethyl sulfoxide (DMSO), H-CDs can serve as optical probes for detecting DMSO in a linear range of 0.005% to 0.75% and with a detection limit of 0.001%.

Paternal and maternal rejection and Chinese children's internalizing and externalizing problems across the transition to siblinghood: A developmental cascade model of family influence.

This longitudinal study examined the reciprocal associations between paternal and maternal rejection and firstborn children's (Mage  = 49.9 months; 55% boys) behavior problems across the transition to siblinghood in a sample of 120 families recruited from 2016 to 2018 from Shanghai, China. Parental rejection and behavior problems were assessed before (prenatal) and 1, 6, and 12 months after the birth of a baby sibling. Random intercept cross-lagged panel models revealed positive relations between internalizing problems and both maternal and paternal rejection, and between externalizing problems and paternal rejection at the between-person level (rs = .32-.37), but only cross-lagged effects from children's internalizing and externalizing problems to maternal rejection at the within-person level (ßs = .30-.54).

A tale of two cities: Chinese mothers' parental burnout and parenting behaviors in Shanghai and Nanning.

PURPOSE: Parental burnout is a psychological syndrome that develops in response to the chronic stressors in one's role as a parent. It can be detrimental to the health and wellbeing of both parents and children and has been empirically proven to result in more negative parenting behaviours. Based on recent research, parental burnout is more prevalent in individualistic cultures. Considering that parenting norms and practices vary greatly across cultures, there could be different effects of parental burnout on parenting practices in different areas. The present study aimed to determine the relationship between parental burnout and parenting behaviours in Shanghai and Nanning, two cities in China that differ in the extent to which they have been exposed to the cultural influence of Western individualism, and to examine the moderating effect of city on these relationship patterns. METHODS: Three hundred and sixty-eight mothers in Shanghai and 180 mothers in Nanning took part in the survey. RESULTS: On average, mothers in Shanghai had more severe parental burnout than their counterparts in Nanning. Furthermore, parental burnout was associated with positive parenting behaviours (i.e., parental warmth) and negative parenting behaviours (i.e., parental hostility and neglect), and the associations between parental burnout and negative parenting behaviours in Nanning were greater than in Shanghai. CONCLUSIONS: These results can be explained by cultural differences in individualism and collectivism between Shanghai and Nanning. This study extends the knowledge on the role of culture in shaping parental roles.

Schiff Base Reaction in a Living Cell: In Situ Synthesis of a Hollow Covalent Organic Polymer To Regulate Biological Functions.

Artificially performing chemical reactions in living biosystems to attain various physiological aims remains an intriguing but very challenging task. In this study, the Schiff base reaction was conducted in cells using Sc(OTf)3 as a catalyst, enabling the in situ synthesis of a hollow covalent organic polymer (HCOP) without external stimuli. The reversible Schiff base reaction mediated intracellular Oswald ripening endows the HCOP with a spherical, hollow porous structure and a large specific surface area. The intracellularly generated HCOP reduced cellular motility by restraining actin polymerization, which consequently induced mitochondrial deactivation, apoptosis, and necroptosis. The presented intracellular synthesis system inspired by the Schiff base reaction has strong potential to regulate cell fate and biological functions, opening up a new strategic possibility for intervening in cellular behavior.

Dynamic Visualization of Endoplasmic Reticulum Stress in Living Cells via a Two-Stage Cascade Recognition Process.

The endoplasmic reticulum (ER) is crucial for the regulation of multiple cellular processes, such as cellular responses to stress and protein synthesis, folding, and posttranslational modification. Nevertheless, monitoring ER physiological activity remains challenging due to the lack of powerful detection methods. Herein, we built a two-stage cascade recognition process to achieve dynamic visualization of ER stress in living cells based on a fluorescent carbon dot (CD) probe, which is synthesized by a facile one-pot hydrothermal method without additional modification. The fluorescent CD probe enables two-stage cascade ER recognition by first accumulating in the ER as the positively charged and lipophilic surface of the CD probe allows its fast crossing of multiple membrane barriers. Next, the CD probe can specifically anchor on the ER membrane via recognition between boronic acids and o-dihydroxy groups of mannose in the ER lumen. The two-stage cascade recognition process significantly increases the ER affinity of the CD probe, thus allowing the following evaluation of ER stress by tracking autophagy-induced mannose transfer from the ER to the cytoplasm. Thus, the boronic acid-functionalized cationic CD probe represents an attractive tool for targeted ER imaging and dynamic tracking of ER stress in living cells.

Exciton Proliferation and Fate of the Topological Mott Insulator in a Twisted Bilayer Graphene Lattice Model.

A topological Mott insulator (TMI) with spontaneous time-reversal symmetry breaking and nonzero Chern number has been discovered in a real-space effective model for twisted bilayer graphene (TBG) at 3/4 filling in the strong coupling limit [1]. However, the finite temperature properties of such a TMI state remain illusive. In this work, employing the state-of-the-art thermal tensor network and the perturbative field-theoretical approaches, we obtain the finite-T phase diagram and the dynamical properties of the TBG model. The phase diagram includes the quantum anomalous Hall and charge density wave phases at low T, and an Ising transition separating them from the high-T symmetric phases. Because of the proliferation of excitons-particle-hole bound states-the transitions take place at a significantly reduced temperature than the mean-field estimation. The exciton phase is accompanied with distinctive experimental signatures in such as in charge compressibilities and optical conductivities close to the transition. Our work explains the smearing of the many-electron state topology by proliferating excitons and opens an avenue for controlled many-body investigations on finite-temperature states in the TBG and other quantum moiré systems.

The positive role of parental attachment and communication in Chinese adolescents' health behavior and mental health during COVID-19.

INTRODUCTION: Given that coronavirus disease 2019 (COVID-19) has largely influenced adolescents' physical and mental health around the globe, it is important to identify protective factors that may promote adolescents' positive adjustment during the pandemic. This study aimed to examine the role of parental attachment and COVID-19 communication in adolescents' health behavior and mental health during COVID-19. METHODS: A total of 442 Chinese parent-adolescent dyads (mean age of adolescents = 13.35 years; 50% girls) completed two-wave longitudinal surveys over the span of 2 months during the pandemic (Wave 1: July 2020; Wave 2: September 2020). At each wave, adolescents reported on their COVID-19-related health behavior, general health behavior, depressive symptoms, and anxiety symptoms. At Wave 1, parent-adolescent attachment security and COVID-19 communication were also assessed. RESULTS: Adolescents' attachment security to parents was associated with their increased COVID-19-related and general health behavior as well as decreased depression and anxiety over 2 months during COVID-19. Moreover, more frequent parent-adolescent COVID-19 communication was associated with adolescents' increased COVID-19-related and general health behavior over time. Notably, attachment security's and COVID-19 communication's associations with health behavior largely remained the same after taking into account both factors simultaneously. In addition, results from exploratory analyses suggest that more frequent COVID-19 communication mediates the link between attachment security and increased health behavior. CONCLUSIONS: These findings highlight the importance of promoting attachment security and COVID-19 communication between parents and adolescents during the pandemic, which may play a positive role in adolescents' health behavior and mental health.

Kondo Holes in the Two-Dimensional Itinerant Ising Ferromagnet Fe3GeTe2.

Heavy Fermion (HF) states emerge in correlated quantum materials due to the intriguing interplay between localized magnetic moments and itinerant electrons but rarely appear in 3d-electron systems due to high itinerancy of d-electrons. Here, an anomalous enhancement of Kondo screening is observed at the Kondo hole of local Fe vacancies in Fe3GeTe2 which is a recently discovered 3d-HF system featuring Kondo lattice and two-dimensional itinerant ferromagnetism. An itinerant Kondo-Ising model is established to reproduce the experimental results and provides insight into the competition between Ising ferromagnetism and Kondo screening. Our work explains the microscopic origin of the d-electron HF states in Fe3GeTe2 and inspires future studies of the enriched quantum many-body effects with Kondo holes.