Stuck between the lines

Rossella Lupacchini

In his search for the ‘essence’ of continuity, Richard Dedekind (1872) discovered the notion of cut. Epistemologically speaking, a cut produces a separation of a simply infinite system into two parts (Stücke) such that all the elements of one part are screened off all the elements of the other. The distinct continuity of a two-state quantum system is encapsulated in the notion of qubit, the basic ‘unit’ of quantum information. A qubit secures an infinite amount of information, which, however, appears to be only penetrable through ‘sections’ of classical bits. Whereas Dedekind’s cuts dwell on the discrete of number theory, the theory of nature is primarily concerned with continuous transformations. In contrast with Dedekind’s line of thought, could the notion of information be derived from a ‘principle’ of continuity?

Suresh k Devanathan, M.L. Bushnell

Abstract—We like to introduce fQuantum, a Quantum Computing Fault Simulator and new quantum computing fault model based on Hadamard, PauliX, PauliY and PauliZ gates, and the traditional stuck-at-1 SA1 and stuck-at-0 SA0 faults. We had close to 100 % fault coverage on most circuits. The problem with lower coverage comes from function gates, which we will deal with, in future versions of this paper. Keywords—fQuantum,Fault Simulator, Quantum Computing I.

Rachel Pei Chin Won

Gershon Kurizki, Goren Gordon

Henry and Eve try to outrace each other, so as to get first to the unique quantum crystals deposited in an underground mine. In his descent into the mine, Henry resorts to coherent transfer. When he tries to return the same way, he gets stuck halfway up, because his entanglement to Eve’s sensors decoheres him. This scenario represents any environment where the interaction of each constituent with the quantum system is weak. Yet, together these many constituents and the system become completely entangled, causing environment-induced decoherence. This consensual narrative on decoherence conceals conceptual hurdles. Where does one draw the line between the system and the environment? How can the unitarity of QM be reconciled, whereby our past and future are interchangeable, with the irreversible evolution of quantum systems under decoherence, culminating in death? The appendix to this chapter describes coherent oscillations in a quantum system and their decay by decoherence.

Niklas Büscher, Stefan Katzenbeisser