# Theoretical Physics

**10 July 2013**

**Time:**n/a

**Location:**

Clare Horseman

Topological quantum computing as a toy model spacetime

Using quantum systems to produce toy models of spacetime can

help us find ways in which quantum mechanics and general relativity are

compatible. In this talk I propose topological measurement-based quantum

computing as a toy spacetime, focussing in particular on the 3D

measurement-based model with active error correction. I will introduce

3D TQC (including its relation to the 2D surface code and to the anyonic

model). I then show how recent work on partial ordering in standard

measurement-based QC by Raussendorf and collaborators can be applied to

3D TQC and thereby, via Malament's theorem, give a causal structure to

the 3D model. I then show various nice properties of the toy spacetime,

including an exact link to the category-theoretic process diagrams of

Abramsky and Coecke. I will finish by showing the relationship between

different spacetime structures in this model, which gives us a novel

perspective on the relationship between entanglement and temporal

progression.

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