Two-dimensional (2D) semiconducting materials such as monolayer MoS₂ are promising candidates for next-generation electronic and optoelectronic applications thanks to their atomic thickness immue to short-channel effects. Yet the high surface-to-volume ratios also make their electronic functionalities sensitive to surrounding environments. One significant manifestation of this sensitivity is the hysteresis effect observed in the transfer curves of the 2D field-effect transistors (FETs). Stable hysteresis windows could contribute to a class of essential electronic components known as charge storage devices. This report introduces two strategies to enable stable hysteresis in MoS₂ transistors: (1) By dimensionality transformation, monolayer MoS₂ can be rolled up into quasi-1D nanoscrolls, where the high-curvature surface exhibits an electric-field enhancement effect, and the open-ended hollow structures can accommodate solvent molecules as charge trapping centers, forming miniaturized memories with sub-microsecond writing/erasing capabilities. (2) By combining core-shell quantum dots (QDs) with monolayer MoS₂, a memory device with a floating-gate-like structure can be formed, the hysteresis window of which significantly depends on the QD structure and allows for long-term storage with minute charge loss (<25%) over 10 years. These inovative findings could pave the way for the development of 2D semiconductors-based memory devices that harness both long retention times and fast writing/erasing operations.

In this work, we propose a novel continuous-variable source-independent quantum random number generator (CV-SI-QRNG) and establish its security through a semidefinite programming (SDP) approach. We also make a finite-size seurity analysis against general attacks by using concentration inequalities for correlated random variables. Unlike previous approaches that rely on the entropic uncertainty relation between two conjugate observables such as Pauli X and Z measurement, our protocol eliminates this requirement by using a single phase-insensitive detector, significantly simplifying the experimental setup. Furthermore, we address a key challenge in continuous-variable quantum protocols: the reliance on photon number cutoff assumptions in numerical methods for security analysis. These cutoff assumptions, while commonly used, are often non-rigorous and can introduce inaccuracies in the security proof, particularly when the system operates in high photon number regimes. To overcome this limitation, we introduce a dimension reduction technique enables us to perform a precise and reliable security analysis without the need for arbitrary cutoff assumptions. By leveraging SDP, our method transforms the security analysis into an optimization problem that can be solved efficiently, providing strong security guarantees for the CV-SI-QRNG protocol. These innovations enhance both the practicality and rigor of continuous-variable quantum random number generation, making it a promising approach for secure cryptographic applications.

Quantum dynamics governs the time evolution of quantum systems. Accurately characterizing these dynamical processes is crucial for deepening our understanding of fundamental physics and advancing quantum technologies. Quantum process tomography (QPT), the standard approach for characterization, reconstructs the representative matrix by preparing informationally complete sets of input states and measuring the output states. However, the experimental and algorithmic complexity of QPT increases dramatically with the size of the quantum system, significantly limiting its applicability to large-scale systems. Weak measurements on pre- and post-selected quantum systems yield generalized outcomes known as weak values. By establishing a direct relationship between weak values and the representative matrix elements, extracting these complex weak values enables the direct characterization of quantum systems. In recent years, this direct scheme has been successfully applied to various quantum states, single-qubit quantum processes, and quantum measurements. However, a universal direct scheme for the characterization of general quantum processes remains unexplored. Here, we propose a generalized weak value form that encompasses quantum processes, enabling the direct characterization of general quantum processes. Experimentally, we demonstrate the feasibility of our scheme by directly characterizing high-dimensional unitary processes, parity-time symmetric processes, two-qubit unitary processes, as well as single-qubit dephasing and amplitude damping processes, and two-qubit general quantum processes in a photonic platform. By generalizing the definition of weak value, our work not only expands the scope of weak measurements but also provides a promising approach for the characterization and exploration of large-scale quantum systems.

Based on the shared quantum entangled state, entanglement-assisted quantum communication presents advantages in increasing channel capacity. Up to now, most of the entanglement-based quantum communications with dense coding are limited to the proof-of-principle experiments. Toward practical application, it is essential to demonstrate entanglement-based quantum communication in fiber channel. Here, we experimentally demonstrate the deterministic entanglement-assisted quantum communication based on the continuous-variable entangled state through commercial fiber channels. By applying the encoding scheme of dense coding, we realize the simultaneously decoding of two non-commuting classical signals submerged in the shot noise of coherent beam with the help of the continuous-variable entangled beam after the transmission in a 10 km fiber channel. We show that the channel capacity of entanglement-assisted communication is higher than that of coherent state when weak classical signals are transmitted through fiber channels. We also experimentally demonstrate the one-sided device-independent random number generation through a 2 km fiber channel. In this experiment, we first distribute EPR steering through the fiber channel between two distant stations, then verify the existence of randomness at the local station, and finally extract quantum random numbers with a generation rate of 7.06 Mbits/s at the remote station, which is 2 km away from the entanglement source. The presented results makes a crucial step toward practical application of continuous-variable entanglement-assisted quantum communication.

The investigation of material growth and evolution mechanisms is of great importance for the controllable synthesis and property manipulation. In this talk, I will discuss our recent efforts in exploring the growth and evolution dynamics of novel transition metal dichalcogenide (TMD) monolayers using (scanning) transmission electron microscopy ((S)TEM) techniques, especially with the focus on the driven effect of surface/interface structures during these processes. We have demonstrated the synthesis of ultra-long MoS₂ nano-channels within MoSe₂ monolayers, based on intrinsic grain boundaries. A strain-driven growth mechanism is proposed that the strain fields near the grain boundaries not only lead to the preferred substitution of selenium by sulfur atoms but also drive the coherent extension and formation of MoS₂ channels [1]. In addition, we have developed a co-deposition strategy to fabricate a wafer-scale network of platinum single-metal-atom-chains within monolayer MoS₂ film. The stable four-coordinated motifs at the zigzag edges of MoS₂ are uncovered to be responsible for the migration of platinum atoms along the growth direction, and the followed connection of inversely oriented MoS₂ domains, obeying a surf-zip dynamic mechanism [2]. Besides, we also unraveled the surface-vacancy [3] guided phase evolution mechanism of PtSe₂, from crystalline structure to amorphous phase. During this process, the sequential generation of selenium vacancies give rise to the decrease of coordination number, the followed displacement of platinum atoms, and the finally complete amorphization of PtSe_x monolayers [4].

In this article, a wide band active inductor based on three common-source amplifiers constructed with N-type transistors is proposed. The simulation results show that the active inductor can operate at a frequency of 2-7GHz, with a variable inductance from 1nH to 10nH, and a quality factor up to 4K. The piezoelectric bulk wave resonator (BAW) filter is the main frequency selective device for 3-10GHz application and widely used in mobile communication, wifi and other fields. The BAW has high-Q but narrowband characteristics, so BAW needs to be integrated with IPD (integrated passive inductor) to achieve broadband filtering. However, The large size and mutual inductance of IPD severely limit the performance of filters, so this article proposes the replacement IPDs with active inductors and combined with BAW to achieve hybrid integration filter to Miniaturized BAW Filter, at same time maintain its performance.