Nature Electronics最新文献

In a p–n junction, the separation of positive and negative charges leads to diode transport, in which charge flows in only one direction. Non-centrosymmetric polar conductors are intrinsic diodes that could be of use in the development of nonlinear applications. Such systems have recently been extended to non-centrosymmetric superconductors, and the superconducting diode effect has been observed. Here, we report an antiferromagnetic diode effect in a centrosymmetric crystal without directional charge separation. We observed large second-harmonic transport in a nonlinear electronic device enabled by the compensated antiferromagnetic state of even-layered MnBi₂Te₄. We show that this antiferromagnetic diode effect can be used to create in-plane field-effect transistors and microwave-energy-harvesting devices. We also show that electrical sum-frequency generation can be used as a tool to detect nonlinear responses in quantum materials.

Data-driven computing is highly dependent on memory performance. Flash memory is presently the dominant non-volatile memory technology but suffers from limitations in terms of speed. Two-dimensional (2D) materials could potentially be used to create ultrafast flash memory. However, due to interface engineering problems, ultrafast non-volatile performance is presently restricted to exfoliated 2D materials, and there is a lack of performance demonstrations with short-channel devices. Here, we report a scalable integration process for ultrafast 2D flash memory that can be used to integrate 1,024 flash-memory devices with a yield of over 98%. We illustrate the approach with two different tunnelling barrier configurations of the memory stack (HfO₂/Pt/HfO₂ and Al₂O₃/Pt/Al₂O₃) and using transferred chemical vapour deposition-grown monolayer molybdenum disulfide. We also show that the channel length of the ultrafast flash memory can be scaled down to sub-10 nm, which is below the physical limit of silicon flash memory. Our sub-10 nm devices offer non-volatile information storage (up to 4 bits) and robust endurance (over 10⁵).

High-density, large-area electronic interfaces are a key component of brain–computer interface technologies. However, current designs typically require patients to undergo invasive procedures, which can lead to various complications. Here, we report a biodegradable and self-deployable tent electrode for brain cortex interfacing. The system can be integrated with multiplexing arrays and a wireless module for near-field communication and data transfer. It can be programmably packaged and self-deployed using a syringe for minimally invasive delivery through a small hole. Following delivery, it can expand to cover an area around 200 times its initial size. The electrode also naturally decomposes within the body after use, minimizing the impact of subsequent removal surgery. Through in vivo demonstrations, we show that our cortical-interfacing platform can be used to stimulate large populations of cortical activities.

Radiofrequency reflectometry can provide fast and sensitive electrical read-out of charge and spin qubits in quantum dot devices coupled to resonant circuits. In situ frequency tuning and impedance matching of the resonator circuit using voltage-tunable capacitors (varactors) is needed to optimize read-out sensitivity, but the performance of conventional semiconductor- and ferroelectric-based varactors degrades substantially in the millikelvin temperature range relevant for solid-state quantum devices. Here we show that strontium titanate and potassium tantalate, materials which can exhibit quantum paraelectric behaviour with large field-tunable permittivity at low temperatures, can be used to make varactors with perfect impedance matching and resonator frequency tuning at 6 mK. We characterize the varactors at 6 mK in terms of their capacitance tunability, dissipative losses and magnetic field insensitivity. We use the quantum paraelectric varactors to optimize the radiofrequency read-out of carbon nanotube quantum dot devices, achieving a charge sensitivity of 4.8 μe Hz^−1/2 and a capacitance sensitivity of 0.04 aF Hz^−1/2.