27 citations · 79 across the 9 of their papers we have counts for
3 papers · 1 filter
A no-go theorem for absolute observed events without inequalities or modal logic
Nick Ormrod, Jonathan Barrett
This paper builds on no-go theorems to the effect that quantum theory is inconsistent with observations being absolute; that is, unique and non-relative. Unlike the existing no-go…
Consistent circuits for indefinite causal order
Augustin Vanrietvelde, Nick Ormrod, Hlér Kristjánsson +1
Over the past decade, a number of quantum processes have been proposed which are logically consistent, yet feature a cyclic causal structure. However, there is no general formal me…
Causal structure in the presence of sectorial constraints, with application to the quantum switch
Nick Ormrod, Augustin Vanrietvelde, Jonathan Barrett
Existing work on quantum causal structure assumes that one can perform arbitrary operations on the systems of interest. But this condition is often not met. Here, we extend the fra…