Body-Effect-Free OLED-on-Silicon Pixel Circuit Based on Capacitive Division to Extend Data Voltage Range

This paper proposes an OLED pixel compensation circuit that copes with threshold voltage variation, narrow data voltage range, and body effect on a backplane of silicon-based transistors. It consists of six PMOS transistors and two capacitors. The data voltage range is extended by the capacitor division with two capacitors, and the connection of both source and gate nodes to the supply voltage makes the driving transistor free from the body effect. In addition, the reference voltage is used to initialize the gate node voltage of the driving transistor as well as to adjust the data voltage region. By the SPICE simulation, it is verified that the current error over the threshold voltage variations of ±10 mV is reduced to be −1.200% to 0.964% at the maximum current range of around 8 nA, and the data voltage range is extended to 3.4 V, compared to the large current error range from −21.46% to 27.36% and the data voltage range of 0.41 V in the basic 2T1C circuit. In addition, the body-effect-free circuit outperforms the latest 4T1C circuit of the current error range from −3.279% to 3.388%.

Transport through several four-quantum-dot topological structures

In this paper, several four-quantum-dot topological structures are designed. The influence of the interdot coupling strength and intradot Coulomb interactions on the conductance is discussed. The location of the anti-resonance band can be manipulated by tuning the interdot coupling strength, which suggests a physical scheme of an effective quantum switch. The Fano anti-resonance peak may evolve into a resonance peak. For the particular value of the interdot coupling strength, two Fano anti-resonances collapse and bound states in the continuum are formed. Moreover, many-body effect makes the number of anti-resonance bands increase. This study provides a theoretical basis for the design of quantum computing devices.

Andreev reflection of fractional quantum Hall quasiparticles

Electron correlation in a quantum many-body state appears as peculiar scattering behaviour at its boundary, symbolic of which is Andreev reflection at a metal-superconductor interface. Despite being fundamental in nature, dictated by the charge conservation law, however, the process has had no analogues outside the realm of superconductivity so far. Here, we report the observation of an Andreev-like process originating from a topological quantum many-body effect instead of superconductivity. A narrow junction between fractional and integer quantum Hall states shows a two-terminal conductance exceeding that of the constituent fractional state. This remarkable behaviour, while theoretically predicted more than two decades ago but not detected to date, can be interpreted as Andreev reflection of fractionally charged quasiparticles. The observed fractional quantum Hall Andreev reflection provides a fundamental picture that captures microscopic charge dynamics at the boundaries of topological quantum many-body states.