A controllable ferroelastic switching in ferroelectric/multiferroic oxides is highly desirable due to the non-volatile strain and possible coupling between lattice and other order parameter in heterostructures. However, a substrate clamping usually inhibits their elastic deformation in thin films without micro/nano-patterned structure so that the integration of the non-volatile strain with thin film devices is challenging. Here, we report that reversible in-plane elastic switching with a non-volatile strain of approximately 0.4% can be achieved in layered-perovskite Bi2WO6 thin films, where the ferroelectric polarization rotates by 90° within four in-plane preferred orientations. Phase-field simulation indicates that the energy barrier of ferroelastic switching in orthorhombic Bi2WO6 film is ten times lower than the one in PbTiO3 films, revealing the origin of the switching with negligible substrate constraint. The reversible control of the in-plane strain in this layered-perovskite thin film demonstrates a new pathway to integrate mechanical deformation with nanoscale electronic and/or magnetoelectronic applications.

The out-of-time-ordered correlators (OTOC) have been established as a fundamental concept for quantifying quantum information scrambling and diagnosing quantum chaotic behavior. Recently, it was theoretically proposed that the OTOC can be used as an order parameter to dynamically detect both equilibrium quantum phase transitions (EQPTs) and dynamical quantum phase transitions (DQPTs) in one-dimensional many-body systems. Here we report the first experimental observation of EQPTs and DQPTs in a quantum spin chain via quench dynamics of OTOC on a nuclear magnetic resonance quantum simulator. We observe that the quench dynamics of both the order parameter and the two-body correlation function cannot detect the DQPTs, but the OTOC can unambiguously detect the DQPTs. Moreover, we demonstrate that the long-time average value of the OTOC in quantum quench signals the equilibrium quantum critical point and ordered quantum phases, thus one can measure the EQPTs from the non-equilibrium quantum quench dynamics. Our experiment paves a way for experimentally investigating DQPTs through OTOCs and for studying the EQPTs through the non-equilibrium quantum quench dynamics with quantum simulators.

Biomimetic human skinlike materials with preferably self-healing ability, high sensitivity for external stimuli, and good adhesiveness against diverse substrates under a wide range of temperatures are of great importance in various applications such as wearable devices, human-motion devices, and soft robotics. However, most of the reported biomimetic human skinlike materials lack memory function, i.e., they cannot memorize the external stimuli once the stimuli disappear. This drawback hinders their applications in mimicking the human skin in real world. Here, a polyacrylamide/Au@polydopamine glycerol–water (GW) hydrogel has been designed to address this challenge. The as-prepared GW hydrogel exhibits a fast self-healing efficiency and good adhesiveness against diverse substrates under a wide range of temperatures (from −15 to 37 °C). Additionally, our GW hydrogel also possesses good perceived ability for external stimuli and subtle/large human motions. Most importantly, resistance memory function has been realized based on our GW hydrogel. These outstanding properties make it potentially significant in mimicking the human skin in real world.

Ferroelectrics, which generate a switchable electric field across the solid–liquid interface, may provide a platform to control chemical reactions (physical properties) using physical fields (chemical stimuli). However, it is challenging to in-situ control such polarization-induced interfacial chemical structure and electric field. Here, we report that construction of chemical bonds at the surface of ferroelectric BiFeO3 in aqueous solution leads to a reversible bulk polarization switching. Combining piezoresponse (electrostatic) force microscopy, X-ray photoelectron spectroscopy, scanning transmission electron microscopy, first-principles calculations and phase-field simulations, we discover that the reversible polarization switching is ascribed to the sufficient formation of polarization-selective chemical bonds at its surface, which decreases the interfacial chemical energy. Therefore, the bulk electrostatic energy can be effectively tuned by H+/OH− concentration. This water-induced ferroelectric switching allows us to construct large-scale type-printing of polarization using green energy and opens up new opportunities for sensing, high-efficient catalysis, and data storage.

A microwave photonic synthetic aperture radar (MWP SAR) is developed and experimentally demonstrated. In the transmitter, microwave photonic frequency doubling is used to generate a linearly-frequency-modulated (LFM) radar signal; while in the receiver, photonic stretch processing is employed to receive the reflection signal. The presented MWP SAR operates in Ku band with a bandwidth of 600MHz, and is evaluated through a series of inverse SAR imaging tests both in a microwave anechoic chamber and in a field trial. Its imaging performance verifies that the proposed MWP SAR works perfect and shows the potential of overcoming the conventional radar bandwidth bottleneck.

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Determination of the histological subtypes of parotid gland masses might be possible based on CT findings and clinical data. A diagnostic strategy with high diagnostic efficiency was established.