Multi-temporality and the ghostly: How communing with times past informs organizational futures

Despite growing interest in time, history, and memory, we lack an understanding of the multi-temporal reality of organizations - how past, present and future intersect to inform organizational life. In assuming that legacies are conveyed from past to present, there has been little theorization on how this works practically. We propose that the lexicon of the ghostly can help. We contribute a theory of ghostly influence from past to future by offering a framework focusing on core moments of organizational existence: foundation, strategic change, and longevity commemoration, and illustrate this use a case study of the consumer goods multinational Procter & Gamble (1930-2010). In showing that organizational ghosts, absent members whose presence is consequential to the actions of living members, are active and dialogical, we illuminate a dialogical interaction missing from other non-linear conceptions of temporality. This emphasizes the performative force of a dynamic past that provides an inference to action in the present and future

Site-Directed Mutagenesis to Assess the Binding Capacity of Class S Protein of Staphylococcus aureus Leucotoxins to the Surface of Polymorphonuclear Cells

Staphylococcal leucotoxins result from the association of class S components and class F component inducing the activation and the permeabilization of the target cells. Like α-toxin, the leucotoxins are pore-forming toxins with more than 70% β-sheet. This was confirmed by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. In addition, threonine 28 of a predicted and conserved β-sheet at the N-terminal extremity of class S proteins composing leucotoxins aligns with histidine 35 of α-toxin, which has a key role in oligomerization of the final pore. Flow cytometry was used to study different aminoacid substitutions of the threonine 28 in order to evaluate its role in the biological activity of these class S proteins. Finally, results show that threonine 28 of the leucotoxin probably plays a role similar to that of histidine 35 of α-toxin. Mutations on this threonin largely influenced the secondary interaction of the class F component and led to inactive toxin

Spin-degeneracy breaking and parity transitions in three-terminal Josephson junctions

Harnessing spin and parity degrees of freedom is of fundamental importance for the realization of emergent quantum devices. Nanostructures embedded in superconductor--semiconductor hybrid materials offer novel and yet unexplored routes for addressing and manipulating fermionic modes. Here we spectroscopically probe the two-dimensional band structure of Andreev bound states in a phase-controlled hybrid three-terminal Josephson junction. Andreev bands reveal spin-degeneracy breaking, with level splitting in excess of 9 GHz, and zero-energy crossings associated to ground state fermion parity transitions, in agreement with theoretical predictions. Both effects occur without the need of external magnetic fields or sizable charging energies and are tuned locally by controlling superconducting phase differences. Our results highlight the potential of multiterminal hybrid devices for engineering quantum states

Zeeman and Orbital Driven Phase Transitions in Planar Josephson Junctions

We perform supercurrent and tunneling spectroscopy measurements on gate-tunable InAs/Al Josephson junctions (JJs) in an in-plane magnetic field, and report on phase shifts in the current-phase relation measured with respect to an absolute phase reference. The impact of orbital effects is investigated by studying multiple devices with different superconducting lead sizes. At low fields, we observe gate-dependent phase shifts of up to ${\varphi_{0}=0.5\pi}$ which are consistent with a Zeeman field coupling to highly-transmissive Andreev bound states via Rashba spin-orbit interaction. A distinct phase shift emerges at larger fields, concomitant with a switching current minimum and the closing and reopening of the superconducting gap. These signatures of an induced phase transition, which might resemble a topological transition, scale with the superconducting lead size, demonstrating the crucial role of orbital effects. Our results elucidate the interplay of Zeeman, spin-orbit and orbital effects in InAs/Al JJs, giving new understanding to phase transitions in hybrid JJs and their applications in quantum computing and superconducting electronics

Flip-chip-based fast inductive parity readout of a planar superconducting island

Properties of superconducting devices depend sensitively on the parity (even or odd) of the quasiparticles they contain. Encoding quantum information in the parity degree of freedom is central in several emerging solid-state qubit architectures. Yet, accurate, non-destructive, and time-resolved parity measurement is a challenging and long-standing issue. Here we report on control and real-time parity measurement in a superconducting island embedded in a superconducting loop and realized in a hybrid two-dimensional heterostructure using a microwave resonator. Device and readout resonator are located on separate chips, connected via flip-chip bonding, and couple inductively through vacuum. The superconducting resonator detects the parity-dependent circuit inductance, allowing for fast and non-destructive parity readout. We resolved even and odd parity states with signal-to-noise ratio SNR $\approx3$ with an integration time of $20~\mu$s and detection fidelity exceeding 98%. Real-time parity measurement showed state lifetime extending into millisecond range. Our approach will lead to better understanding of coherence-limiting mechanisms in superconducting quantum hardware and provide novel readout schemes for hybrid qubits

Microwave-induced conductance replicas in hybrid Josephson junctions without Floquet-Andreev states

Light-matter interaction enables engineering of non-equilibrium quantum systems. In condensed matter, spatially and temporally cyclic Hamiltonians are expected to generate energy-periodic Floquet states, with properties inaccessible at thermal equilibrium. A recent work explored the tunnelling conductance of a planar Josephson junction under microwave irradiation, and interpreted replicas of conductance features as evidence of steady Floquet-Andreev states. Here we realise a similar device in a hybrid superconducting-semiconducting heterostructure, which utilises a tunnelling probe with gate-tunable transparency and allows simultaneous measurements of Andreev spectrum and current-phase relation of the planar Josephson junction. We show that, in our devices, spectral replicas in sub-gap conductance emerging under microwave irradiation are caused by photon assisted tunnelling of electrons into Andreev states. The current-phase relation under microwave irradiation is also explained by the interaction of Andreev states with microwave photons, without the need to invoke Floquet states. The techniques outlined in this study establish a baseline to distinguish photon assisted tunnelling from Floquet-Andreev states in mesoscopic devices, a crucial development towards understanding light-matter coupling in hybrid nanostructures

Control over epitaxy and the role of the InAs/Al interface in hybrid two-dimensional electron gas systems

In-situ synthesised semiconductor/superconductor hybrid structures became an important material platform in condensed matter physics. Their development enabled a plethora of novel quantum transport experiments with focus on Andreev and Majorana physics. The combination of InAs and Al has become the workhorse material and has been successfully implemented in the form of one-dimensional structures and two-dimensional electron gases. In contrast to the well-developed semiconductor parts of the hybrid materials, the direct effect of the crystal nanotexture of Al films on the electron transport still remains unclear. This is mainly due to the complex epitaxial relation between Al and the semiconductor. We present a study of Al films on shallow InAs two-dimensional electron gas systems grown by molecular beam epitaxy, with focus on control of the Al crystal structure. We identify the dominant grain types present in our Al films and show that the formation of grain boundaries can be significantly reduced by controlled roughening of the epitaxial interface. Finally, we demonstrate that the implemented roughening does not negatively impact either the electron mobility of the two-dimensional electron gas or the basic superconducting properties of the proximitized system.Comment: 12 pages, 7 figures and supplementary materia

History in organization and management theory: more than meets the eye

There has been a growing debate about the role of history in management research with several authors making suggestions on how to bring the two (back) together and others even highlighting the need for a “historic turn”. What we argue in this paper is that, while history was indeed sidelined by the scientization of management since the late 1950s, it started to make a comeback from the 1980s onwards and is increasingly employed in a number of research programs. We stress that the crucial question for management scholars engaging with history (or wanting to do so) is how it relates to theory. First of all, we present a systematic overview of the way history has been used—both at the micro (organizational) and macro-levels of analysis—distinguishing between what we refer to as “history to theory” and “history in theory”. In the former, we consider those research programs, such as (neo-)institutionalism, where history serves as evidence to develop, modify or test theories. In the case of “history in theory” we identify research programs where history or the past are part of the theoretical model itself as a driver or moderator, with “imprinting” as a prime example. Second, we also identify a growing number of studies that go further by displaying what we call “historical cognizance” in the sense of incorporating period effects or historical contingencies into their theorizing efforts. Finally, drawing on our broad overview, we make more specific suggestions for increasing the visibility and influence of history in organization and management theory

Historical Narratives and the Defense of Stigmatized Industries

This study examines how managers and entrepreneurs in stigmatized industries use historical narratives to combat stigma. We examine two industries, the private military contractors (PMC) industry in the United States and the cannabis industry in Canada. In recent decades, the representatives of these industries have worked to reduce the level of stigmatization faced by the industries. We show that historical narratives were used rhetorically by the representatives of both industries. In both cases, these historical narratives were targeted at just one subset of the population. Our research contributes to debates about stigmatization in ideologically diverse societies, an important issue that have been overlooked by the existing literature on stigmatized industries, which tends to assume the existence of homogeneous audiences when researching the efforts of industry representatives to destigmatize their industries