Simultaneously enhanced magnomechanical cooling and entanglement assisted by an auxiliary microwave cavity.

We propose a mechanism to simultaneously enhance quantum cooling and entanglement via coupling an auxiliary microwave cavity to a magnomechanical cavity. The auxiliary cavity acts as a dissipative cold reservoir that can efficiently cool multiple localized modes in the primary system via beam-splitter interactions, which enables us to obtain strong quantum cooling and entanglement. We analyze the stability of the system and determine the optimal parameter regime for cooling and entanglement under the auxiliary-microwave-cavity-assisted (AMCA) scheme. The maximum cooling enhancement rate of the magnon mode can reach 98.53%, which clearly reveals that the magnomechanical cooling is significantly improved in the presence of the AMCA. More importantly, the dual-mode entanglement of the system can also be significantly enhanced by AMCA in the full parameter region, where the initial magnon-phonon entanglement can be maximally enhanced by a factor of about 11. Another important result of the AMCA is that it also increases the robustness of the entanglement against temperature. Our approach provides a promising platform for the experimental realization of entanglement and quantum information processing based on cavity magnomechanics.

Origin of Interfacial Orbital Reconstruction in Perovskite Superlattices.

The competition between on-site electronic correlation and local crystal field stands out as a captivating topic in research. However, its physical ramifications often get overshadowed by influences of strong periodic potential and orbital hybridization. The present study reveals this competition may become more pronounced or even dominant in two-dimensional systems, driven by the combined effects of dimensional confinement and orbital anisotropy. This leads to electronic orbital reconstruction in certain perovskite superlattices or thin films. To explore the emerging physics, we investigate the interfacial orbital disorder-order transition with an effective Hamiltonian and how to modulate this transition through strains.

Social distancing mediated generalized model to predict epidemic spread of COVID-19.

The extensive proliferation of recent coronavirus (COVID-19), all over the world, is the outcome of social interactions through massive transportation, gatherings and population growth. To disrupt the widespread of COVID-19, a mechanism for social distancing is indispensable. Also, to predict the effectiveness and quantity of social distancing for a particular social network, with a certain contagion, a generalized model is needed. In this manuscript, we propose a social distancing mediated generalized model to predict the pandemic spread of COVID-19. By considering growth rate as a temporal harmonic function damped with social distancing in generalized Richard model and by using the data of confirmed COVID-19 cases in China, USA and India, we find that, with time, the cumulative spread grows more rapidly due to weak social distancing as compared to the stronger social distancing, where it is explicitly decreasing. Furthermore, we predict the possible outcomes with various social distancing scenarios by considering highest growth rate as an initial state, and illustrate that the increase in social distancing tremendously decreases growth rate, even it tends to reach zero in lockdown regimes. Our findings not only provide epidemic growth scenarios as a function of social distancing but also provide a modified growth model to predict controlled information flow in any network.

Finite-Component Multicriticality at the Superradiant Quantum Phase Transition.

We demonstrate the existence of finite-component multicriticality in a qubit-boson model where biased qubits collectively coupled to a single-mode bosonic field. The interplay between biases and boson-qubit coupling produces a rich phase diagram which shows multiple superradiant phases and phase boundaries of different orders. In particular, multiple phases become indistinguishable in appropriate bias configurations, which is the signature of multicriticality. A series of universality classes characterizing these multicritical points are identified. Moreover, we present a trapped-ion realization with the potential to explore multicritical phenomena experimentally using a small number of ions. The results open a novel way to probe multicritical universality classes in experiments.

Universal Dissipationless Dynamics in Gaussian Continuous-Variable Open Systems.

We investigate the universal dissipationless dynamics of Gaussian continuous-variable systems in the presence of a band-gapped bosonic environment. Our results show that environmental band gaps can induce localized modes, which give rise to the dissipationless dynamics where the system behaves as free oscillators instead of experiencing a full decay in the long-time limit. We present a complete characterization of localized modes and show the existence of the critical system-environment coupling. Beyond the critical values, localized modes can be produced, and the system dynamics become dissipationless. This novel dynamics can be utilized to overcome the environmental noises and protect the quantum resources in the continuous-variable quantum information.

Inhibiting the self-discharging process of quantum batteries in non-Markovian noises.

One of the main challenges in developing high-performance quantum batteries is the self-discharging process, where energy is dissipated from a quantum battery into the environment. In this work, we investigate the influence of non-Markovian noises on the performance of a quantum battery. Our results demonstrate that adding auxiliary qubits to a quantum battery system can effectively suppress the self-discharging process, leading to an improvement in both the steady-state energy and extractable work. We reveal that the physical mechanism inhibiting the self-discharging process is the formation of system-environment bound states, rather than an increase in non-Markovianity. Our results could be of both theoretical and experimental interest in exploring the ability of quantum batteries to maintain long stored energy in the environment.

Milk fat globule epidermal growth factor 8 alleviates liver injury in severe acute pancreatitis by restoring autophagy flux and inhibiting ferroptosis in hepatocytes.

BACKGROUND: Liver injury is common in severe acute pancreatitis (SAP). Excessive autophagy often leads to an imbalance of homeostasis in hepatocytes, which induces lipid peroxidation and mitochondrial iron deposition and ultimately leads to ferroptosis. Our previous study found that milk fat globule epidermal growth factor 8 (MFG-E8) alleviates acinar cell damage during SAP via binding to αvß3/5 integrins. MFG-E8 also seems to mitigate pancreatic fibrosis via inhibiting chaperone-mediated autophagy. AIM: To speculate whether MFG-E8 could also alleviate SAP induced liver injury by restoring the abnormal autophagy flux. METHODS: SAP was induced in mice by 2 hly intraperitoneal injections of 4.0 g/kg L-arginine or 7 hly injections of 50 µg/kg cerulein plus lipopolysaccharide. mfge8-knockout mice were used to study the effect of MFG-E8 deficiency on SAP-induced liver injury. Cilengitide, a specific αvß3/5 integrin inhibitor, was used to investigate the possible mechanism of MFG-E8. RESULTS: The results showed that MFG-E8 deficiency aggravated SAP-induced liver injury in mice, enhanced autophagy flux in hepatocyte, and worsened the degree of ferroptosis. Exogenous MFG-E8 reduced SAP-induced liver injury in a dose-dependent manner. Mechanistically, MFG-E8 mitigated excessive autophagy and inhibited ferroptosis in liver cells. Cilengitide abolished MFG-E8's beneficial effects in SAP-induced liver injury. CONCLUSION: MFG-E8 acts as an endogenous protective mediator in SAP-induced liver injury. MFG-E8 alleviates the excessive autophagy and inhibits ferroptosis in hepatocytes by binding to integrin αVß3/5.

Rydberg polaritons in a cavity: a superradiant solid.

We study an optical cavity coupled to a lattice of Rydberg atoms, which can be represented by a generalized Dicke model. We show that the competition between the atom-atom interaction and atom-light coupling induces a rich phase diagram. A novel superradiant solid (SRS) phase is found, where both the superradiance and crystalline orders coexist. Different from the normal second order superradiance transition, here both the solid-1/2 and SRS to SR phase transitions are first order. These results are confirmed by large scale quantum Monte Carlo simulations.

Multi-Wavelength Selective and Broadband Near-Infrared Plasmonic Switches in Anisotropic Plasmonic Metasurfaces.

Anisotropic plasmonic metasurfaces have attracted broad research interest since they possess novel optical properties superior to natural materials and their tremendous design flexibility. However, the realization of multi-wavelength selective plasmonic metasurfaces that have emerged as promising candidates to uncover multichannel optical devices remains a challenge associated with weak modulation depths and narrow operation bandwidth. Herein, we propose and numerically demonstrate near-infrared multi-wavelength selective passive plasmonic switching (PPS) that encompasses high ON/OFF ratios and strong modulation depths via multiple Fano resonances (FRs) in anisotropic plasmonic metasurfaces. Specifically, the double FRs can be fulfilled and dedicated to establishing tailorable near-infrared dual-wavelength PPS. The multiple FRs mediated by in-plane mirror asymmetries cause the emergence of triple-wavelength PPS, whereas the multiple FRs governed by in-plane rotational asymmetries avail the implementation of the quasi-bound states in the continuum-endowed multi-wavelength PPS with the ability to unfold a tunable broad bandwidth. In addition, the strong polarization effects with in-plane anisotropic properties further validate the existence of the polarization-resolved multi-wavelength PPS. Our results provide an alternative approach to foster the achievement of multifunctional meta-devices in optical communication and information processing.

Observation of Rydberg moiré excitons.

Rydberg excitons, the solid-state counterparts of Rydberg atoms, have sparked considerable interest with regard to the harnessing of their quantum application potentials, but realizing their spatial confinement and manipulation poses a major challenge. Lately, the rise of two-dimensional moiré superlattices with highly tunable periodic potentials provides a possible pathway. Here, we experimentally demonstrate this capability through the spectroscopic evidence of Rydberg moiré excitons (XRM), which are moiré-trapped Rydberg excitons in monolayer semiconductor tungsten diselenide adjacent to twisted bilayer graphene. In the strong coupling regime, the XRM manifest as multiple energy splittings, pronounced red shift, and narrowed linewidth in the reflectance spectra, highlighting their charge-transfer character wherein electron-hole separation is enforced by strongly asymmetric interlayer Coulomb interactions. Our findings establish the excitonic Rydberg states as candidates for exploitation in quantum technologies.

Tuning the tricritical point with spin-orbit coupling in polarized fermionic condensates.

We investigate a two-component atomic Fermi gas with population imbalance in the presence of Rashba-type spin-orbit coupling (SOC). As a competition between SOC and population imbalance, the finite-temperature phase diagram reveals a large variety of new features, including the expanding of the superfluid state regime and the shrinking of both the phase separation and the normal regimes. For sufficiently strong SOC, the phase separation region disappears, giving way to the superfluid state. We find that the tricritical point moves toward a regime of low temperature, high magnetic field, and high polarization as the SOC increases.

Kondo metal and ferrimagnetic insulator on the triangular kagome lattice.

We obtain the rich phase diagrams in the Hubbard model on the triangular kagome lattice as a function of interaction, temperature, and asymmetry by combining the cellular dynamical mean-field theory with the continuous time quantum Monte Carlo method. The phase diagrams show the asymmetry separates the critical points in the Mott transition of two sublattices on the triangular kagome lattice and produces two novel phases called plaquette insulator with a clearly visible gap and a gapless Kondo metal. When the Coulomb interaction is stronger than the critical value U(c), a short range paramagnetic insulating state, which is a candidate for the short rang resonating valence-bond spin liquid, emerges before the ferrimagnetic order is formed independent of asymmetry. Furthermore, we discuss how to measure these phases in future experiments.

Topological transition and Majorana zero modes in 2D non-Hermitian chiral superconductor with anisotropy.

We study a non-Hermitian chiral topological superconductor system on two dimensional square lattice, from which we obtained a rich topological phase diagram and established an exact relationship between topological charge flow of exceptional points in generalized Brillouin zone and change of topological properties. Its rich topological phase diagram is the result of competition between anisotropy and non-Hermitian effect. This system belongs to class D according to AZ classification of non-Hermitian systems. Each topological phase can be characterized by a 2DZnumber, which indicates the number of chiral edge modes, and two 1DZ2numbers, which indicate the existence of zero modes at edge dislocations.

Non-Floquet engineering in periodically driven dissipative open quantum systems.

Floquet engineering plays a key role in realizing novel dynamical topological states. The conventional Floquet engineering, however, only applies to time-periodic non-dissipative Hermitian systems, and for the open quantum systems, non-Hermitian processes usually occur. So far, it remains unclear how to characterize the topological phases of time-periodic open quantum systems via the frequency space Floquet Hamiltonian. Here, we propose the non-Floquet theory to solve the problem and illustrate it by a continuously time-periodic non-Hermitian bipartite chain. In non-Floquet theory, a temporal non-unitary transformation is exercised on the Floquet states, and the transformed Floquet spectrum restores the form of the Wannier-Stark ladder. Besides, we also show that different choices of the starting points of the driving period can result in different localization behavior, effects of which can reversely be utilized to design quantum detectors of phases in dissipative oscillating fields. Our methods are capable of describing topological features in dynamical open quantum systems with various driving types and can find its applications to construct new types of dynamical topological materials.

First-order metal-ferromagnetic insulator phase transition induced by Rashba spin-orbit coupling on the puckered honeycomb lattice.

We investigate the first-order metal-ferromagnetic insulator phase transition on the puckered honeycomb lattice, combining the cellular dynamical mean field theory with the continuous-time quantum Monte Carlo method. By analyzing the interplay among intrinsic spin-orbit coupling (SOC), Rashba SOC and on-site interaction, we show that the ferromagnetic (FM) order and the antiferromagnetic (AFM) order occur in different regimes. Rashba SOC allows the electron spin flipping, which leads to the phase transition from the metal to FM insulator induced by the increasing on-site interaction. In contrast to the usual continuous metal-antiferromagnetic insulator phase transition, we find that the metal-ferromagnetic insulator transition is first-order by computing the double occupancy. Furthermore, the complete phase diagrams of the Rashba SOC, on-site interaction and temperature are also demonstrated.

Ergodic time scale and transitive dynamics in single-particle tracking.

We investigate ergodic time scales in single-particle tracking by introducing a covariance measure Ω(Δ;t) for the time-averaged relative square displacement recorded in lag-time Δ at elapsed time t. The present model is established in the generalized Langevin equation with a power-law memory function. The ratio Ω(Δ;Δ)/Ω(Δ;t) is shown to obey a universal scaling law for long but finite times and is used to extract the effective ergodic time. We derive a finite-time-averaged Green-Kubo relation and find that, to control the deviations in measurement results from ensemble averages, the ratio Δ/t must be neither too small nor close to unity. Our paper connects the experimental self-averaging property of a tracer with the theoretic velocity autocorrelation function and sheds light on the transition to ergodicity.

Enhancing the performance of an open quantum battery via environment engineering.

We investigate the charging process of open quantum battery in the weak system-environment coupling regime. A method to improve the performance of open quantum battery in a reservoir environment, which described by a band-gap environment model or a two-Lorentzian environment model, is proposed by manipulating the spectral density of environment. We find that the optimal quantum battery, characterized by fast charging time and large ergotropy, in the band-gap environment can be obtained by increasing the weights of two Lorentzians and the spectral width of the second Lorentzian, which is in sharp contrast to the quantum battery in two-Lorentzian environment. Then we extend our discussion to multiple coupled reservoir environments, which are composed of N coupled dissipative cavities. We show that, the performance of quantum battery can be enhanced by increasing the coupling strength between the nearest-neighbor environments and decreasing the size of the environments. In particular, to fully charge and extract the total stored energy as work for quantum battery can be achieved by manipulating the coupling strength between the nearest-neighbor environments. Our results provide a practical approach for the realization of the optimal quantum batteries in future experiments.

Superfluid density and collective modes of fermion superfluid in dice lattice.

The superfluid properties of attractive Hubbard model in dice lattice are investigated. It is found that three superfluid order parameters increase as the interaction increases. When the filling factor falls into the flat band, due to the infinite large density of states, the resultant superfluid order parameters are proportional to interaction strength, which is in striking contrast with the exponentially small counterparts in usual superfluid (or superconductor). When the interaction is weak, and the filling factor is near the bottom of the lowest band (or the top of highest band), the superfluid density is determined by the effective mass of the lowest (or highest) single-particle band. When the interaction is strong and filling factor is small, the superfluid density is inversely proportional to interaction strength, which is related to effective mass of tightly bound pairs. In the strong interaction limit and finite filling, the asymptotic behaviors of superfluid density can be captured by a parabolic function of filling factor. Furthermore, when the filling is in flat band, the superfluid density shows a logarithmic singularity as the interaction approaches zero. In addition, there exist three undamped collective modes for strong interactions. The lowest excitation is gapless phonon, which is characterized by the total density oscillations. The two others are gapped Leggett modes, which correspond relative density fluctuations between sublattices. The collective modes are also reflected in the two-particle spectral functions by sharp peaks. Furthermore, it is found that the two-particle spectral functions satisfy an exact sum-rule, which is directly related to the filling factor (or density of particle). The sum-rule of the spectral functions may be useful to distinguish between the hole-doped and particle-doped superfluid (superconductor) in experiments.

T-tube vs no T-tube for biliary tract reconstruction in adult orthotopic liver transplantation: An updated systematic review and meta-analysis.

BACKGROUND: Whether to use a T-tube for biliary anastomosis during orthotopic liver transplantation (OLT) remains a debatable question. Some surgeons chose to use a T-tube because they believed that it reduces the incidence of biliary strictures. Advances in surgical techniques during the last decades have significantly decreased the overall incidence of postoperative biliary complications. Whether using a T-tube during OLT is still associated with the reduced incidence of biliary strictures needs to be re-evaluated. AIM: To provide an updated systematic review and meta-analysis on using a T-tube during adult OLT. METHODS: In the electronic databases MEDLINE, PubMed, Scopus, ClinicalTrials.gov, the Cochrane Library, the Cochrane Hepato-Biliary Group Controlled Trails Register, and the Cochrane Central Register of Controlled Trials, we identified 17 studies (eight randomized controlled trials and nine comparative studies) from January 1995 to October 2020. The data of the studies before and after 2010 were separately extracted. We chose the overall biliary complications, bile leaks or fistulas, biliary strictures (anastomotic or non-anastomotic), and cholangitis as outcomes. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to describe the results of the outcomes. Furthermore, the test for overall effect (Z) was used to test the difference between OR and 1, where P ≤ 0.05 indicated a significant difference between OR value and 1. RESULTS: A total of 1053 subjects before 2010 and 1346 subjects after 2010 were included in this meta-analysis. The pooled results showed that using a T-tube reduced the incidence of postoperative biliary strictures in studies before 2010 (P = 0.012, OR = 0.62, 95%CI: 0.42-0.90), while the same benefit was not seen in studies after 2010 (P = 0.60, OR = 0.76, 95%CI: 0.27-2.12). No significant difference in the incidence of overall biliary complications (P = 0.37, OR = 1.41, 95%CI: 0.66-2.98), bile leaks (P = 0.89, OR = 1.04, 95%CI: 0.63-1.70), and cholangitis (P = 0.27, OR = 2.00, 95%CI: 0.59-6.84) was observed between using and not using a T-tube before 2010. However, using a T-tube appeared to increase the incidence of overall biliary complications (P = 0.049, OR = 1.49, 95%CI: 1.00-2.22), bile leaks (P = 0.048, OR = 1.91, 95%CI: 1.01-3.64), and cholangitis (P = 0.02, OR = 7.21, 95%CI: 1.37-38.00) after 2010. A random-effects model was used in biliary strictures (after 2010), overall biliary complications (before 2010), and cholangitis (before 2010) due to their heterogeneity (I 2 = 62.3%, 85.4%, and 53.6%, respectively). In the sensitivity analysis (only RCTs included), bile leak (P = 0.66) lost the significance after 2010 and a random-effects model was used in overall biliary complications (before 2010), cholangitis (before 2010), bile leaks (after 2010), and biliary strictures (after 2010) because of their heterogeneity (I 2 = 92.2%, 65.6%, 50.9%, and 80.3%, respectively). CONCLUSION: In conclusion, the evidence gathered in our updated meta-analysis showed that the studies published in the last decade did not provide enough evidence to support the routine use of T-tube in adults during OLT.

Robust Majorana edge modes with low frequency multiple time periodic driving.

Floquet Majorana edge modes capture the topological features of periodically driven p-wave superconductors. We present a Kitaev chain with multiple time periodic driving terms. Our results demonstrate how multiple driving will affect Floquet bands in frequency space, leading to more robust Floquet Majorana edge modes against driving frequency ω in comparison with the single driving scenario. Meanwhile, we have proposed how to predict Majorana edge modes via the Zak phase of Floquet bands. Besides, in contrast to the cases with single driving term, where the constant phase can be gauged out by properly choosing the initial time, we have shown the relative phase between multiple driving can not be gauged out and will play a dominant role in deciding topological phase transitions. For the sake of completeness, we also investigate the high frequency limit. Analytical results on effective Hamiltonian can be obtained via Magnus expansion and relative phase induced topological transitions can be shown explicitly.