<p>We study the abelian sub-<InlineEquation ID="IEq4"> <EquationSource Format="TEX">\(C^*\)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>C</mi> <mo>∗</mo> </msup> </math></EquationSource> </InlineEquation>-algebra of the <InlineEquation ID="IEq5"> <EquationSource Format="TEX">\(2^\infty \)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mn>2</mn> <mi>∞</mi> </msup> </math></EquationSource> </InlineEquation>-UHF algebra generated by the star and face operators of Kitaev’s toric code. We show that it is a <InlineEquation ID="IEq6"> <EquationSource Format="TEX">\(C^*\)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>C</mi> <mo>∗</mo> </msup> </math></EquationSource> </InlineEquation>-diagonal equivalent to the canonical diagonal of <InlineEquation ID="IEq7"> <EquationSource Format="TEX">\(M_{2^\infty }\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>M</mi> <msup> <mn>2</mn> <mi>∞</mi> </msup> </msub> </math></EquationSource> </InlineEquation>.</p>
We study the abelian sub-\(C^*\)-algebra of the \(2^\infty \)-UHF algebra generated by the star and face operators of Kitaev’s toric code. We show that it is a \(C^*\)-diagonal equivalent to the canonical diagonal of \(M_{2^\infty }\).