Ambulation in patients with peripheral veno-arterial extracorporeal membrane oxygenation and concomitant femoral intra-aortic balloon pump support.

Introduction: The mobilization and ambulation of patients with severe cardiogenic shock supported with peripheral veno-arterial extracorporeal membrane oxygenation (pVA-ECMO) and concomitant femoral intra-aortic balloon pump (IABP) support is not well-described. This technical paper describes an ambulation protocol to prevent deconditioning in this critically ill patient population.

Methods: A protocol for the ambulation of patients with pVA-ECMO and concomitant IABP support was created in December 2022 and implemented at a single center.

Microstrip filters for measurement and control of superconducting qubits.

Careful filtering is necessary for observations of quantum phenomena in superconducting circuits at low temperatures. Measurements of coherence between quantum states require extensive filtering to protect against noise coupled from room temperature electronics. We demonstrate distributed transmission line filters which cut off exponentially at GHz frequencies and can be anchored at the base temperature of a dilution refrigerator.

Effect of measurement on the periodicity of the Coulomb staircase of a superconducting box.

We report on the effect of the backaction of a single Cooper pair transistor electrometer (E) on the charge state of a superconducting box (B). The charge is e periodic in the gate bias of B when E is operated near voltages 2 Delta/e or 4 Delta/e. We show that this is due to quasiparticle poisoning of B at a rate proportional to the number of quasiparticle tunneling events in E per second.

Universal distribution of transparencies in highly conductive Nb/AlO(x)/Nb junctions.

We report the observation of the universal distribution of transparencies, predicted by Schep and Bauer [Phys. Rev. Lett.

Observation of cascaded two-photon-induced transitions between fluxoid states of a SQUID.

We present evidence for transitions between fluxoid wells of a SQUID due to cascaded, two-photon processes. Such transitions are evidenced by an anomalous dependence on the transition rate from the one-photon resonant level within the initial well, which cannot be explained by previously observed macroscopic resonant tunneling. These two-photon processes may be a significant source of decoherence in SQUID qubits subject to microwave radiation.

Quantum superposition of distinct macroscopic states.

In 1935, Schrodinger attempted to demonstrate the limitations of quantum mechanics using a thought experiment in which a cat is put in a quantum superposition of alive and dead states. The idea remained an academic curiosity until the 1980s when it was proposed that, under suitable conditions, a macroscopic object with many microscopic degrees of freedom could behave quantum mechanically, provided that it was sufficiently decoupled from its environment. Although much progress has been made in demonstrating the macroscopic quantum behaviour of various systems such as superconductors, nanoscale magnets, laser-cooled trapped ions, photons in a microwave cavity and C60 molecules, there has been no experimental demonstration of a quantum superposition of truly macroscopically distinct states.