We utilize electron counting techniques to distinguish a spin-conserving fast tunneling process and a slower process involving spin flips in AlGaAs/GaAs-based double quantum dots. By studying the ...dependence of the rates on the interdot tunnel coupling of the two dots, we find that as many as 4% of the tunneling events occur with a spin flip related to spin-orbit coupling in GaAs. Our measurement has a fidelity of 99% in terms of resolving whether a tunneling event occurred with a spin flip or not.
Purpose
The objectives of this study were to verify and group the unintended consequences (UCs) of performance evaluation systems (PESs) reported by empirical studies in the literature; and to ...determine whether these consequences manifest themselves at the managerial or the operational level of organisations.
Design/methodology/approach
A systematic review of the literature was undertaken using the intervention instrument Knowledge Development Process-Constructivist. In total, 33 scientifically relevant empirical articles were selected from the Scopus and Web of Science databases, representative of the theme of PESs’ UCs. The treatment of the data was due to critical reflection on the findings, synthesized in a literature map.
Findings
The study identified 24 UCs, most of which were negative. These were divided into two categories: feelings/emotions and attitudes/implications. Most conscious attitudes manifested themselves at the managerial level, whereas the unconscious ones appeared at the operational level. It was established that employees are more likely to be induced to adopt dysfunctional behaviours. Social aspects that interact with a PES, such as contextual and cultural factors, are fundamental for understanding how PES’s UCs occur.
Originality/value
The study provides insights for researchers and professionals in the field of performance evaluation who wish to delve deeper into the theme of UCs, based on the proposed structure of a literature map that consists of dividing consequences into feelings and attitudes; checking the occurrence level (managerial or operational); and identifying the nature of the attitude, whether it is conscious or unconscious.
Quantum states in graphene are 2-fold degenerate in spins, and 2-fold in valleys. Both degrees of freedom can be utilized for qubit preparations. In our bilayer graphene quantum dots, we demonstrate ...that the valley g-factor g v, defined analogously to the spin g-factor g s for valley splitting in a perpendicular magnetic field, is tunable by over a factor of 4 from 20 to 90, by gate voltage adjustments only. Larger g v results from larger electronic dot sizes, determined from the charging energy. On our versatile device, bipolar operation, charging our quantum dot with charge carriers of the same or the opposite polarity as the leads, can be performed. Dots of both polarities are tunable to the first charge carrier, such that the transition from an electron to a hole dot by the action of the plunger gate can be observed. Addition of gates easily extends the system to host tunable double dots.
Magic-angle twisted bilayer graphene can host a variety of gate-tunable correlated states - including superconducting and correlated insulator states. Recently, junction-based superconducting moiré ...devices have been introduced, enabling the study of the charge, spin and orbital nature of superconductivity, as well as the coherence of moiré electrons in magic-angle twisted bilayer graphene. Complementary fundamental coherence effects-in particular, the Little-Parks effect in a superconducting ring and the Aharonov-Bohm effect in a normally conducting ring - have not yet been reported in moiré devices. Here, we observe both phenomena in a single gate-defined ring device, where we can embed a superconducting or normally conducting ring in a correlated or band insulator. The Little-Parks effect is seen in the superconducting phase diagram as a function of density and magnetic field, confirming the effective charge of 2e. We also find that the coherence length of conducting moiré electrons exceeds several microns at 50 mK. In addition, we identify a regime characterized by h/e-periodic oscillations but with superconductor-like nonlinear transport.
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