Homological bosonic code[1]


An \([[n,1]]_{\mathbb{R}}\) oscillator-into-oscillator CSS stabilizer code defined using homological structres associated with an \(n-1\) simplex. Relevant to the study of spacetime replication of quantum information [2].

Stabilizer generators are defined by two orthogonal subspaces of the \(C_1\) in the chain complex. \(C_X = \partial_2 C_2\) and \(C_P = \partial_1^T Q\) for some \(Q \subset C_0\). The standard approach would use \(Q = C_0\), which would mean the logical dimension would be the dimension of the 1st homology group \(H^1\). However, \(H^1\) is trivial for the \(n-1\) simplex, so one chooses \(Q \neq C_0\) such that exactly one stabilizer is removed, yielding a stabilizer code instead of a single stabilized state.'


Protects against certain types of erasure errors (depending on the specific dimension). Certain constructions also protect arbitrary sized errors on multiple photon states.


Encoding depends on the specific dimension, but can generally be done using generalized conditional-rotation and Fourier-transform gates.


Decoding requires a different circuit for each possible erasure error, with no general circuit decoding any possible erasure error. Every circuit relies on a generalized conditional rotation, which Ref. [1] calls the QND Gate and which is defined as \(QND_c | x , y \rangle = |x + c y, y \rangle\).


No experimental realization. However, Ref. [1] describes a potential experimental optical procedure for the simplest non-trival code with 5 modes.



  • Calderbank-Shor-Steane (CSS) stabilizer code — CSS and homological CV codes utilize chain complexes in code construction, with the latter complexes having trivial homology.
  • Niset-Andersen-Cerf code — The Niset-Andersen-Cerf code can be viewed as a scheme to replicate quantum information in multiple regions [1].
  • Spacetime code (STC) — Homological CV codes have been considered in the context of spacetime replication of quantum data [2][1], while STCs are designed to replicate classical data.

Zoo code information

Internal code ID: homological_cv

Your contribution is welcome!

on github.com (edit & pull request)

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Zoo Code ID: homological_cv

Cite as:
“Homological bosonic code”, The Error Correction Zoo (V. V. Albert & P. Faist, eds.), 2022. https://errorcorrectionzoo.org/c/homological_cv
@incollection{eczoo_homological_cv, title={Homological bosonic code}, booktitle={The Error Correction Zoo}, year={2022}, editor={Albert, Victor V. and Faist, Philippe}, url={https://errorcorrectionzoo.org/c/homological_cv} }
Permanent link:


P. Hayden et al., “Spacetime replication of continuous variable quantum information”, New Journal of Physics 18, 083043 (2016). DOI; 1601.02544
P. Hayden and A. May, “Summoning information in spacetime, or where and when can a qubit be?”, Journal of Physics A: Mathematical and Theoretical 49, 175304 (2016). DOI; 1210.0913

Cite as:

“Homological bosonic code”, The Error Correction Zoo (V. V. Albert & P. Faist, eds.), 2022. https://errorcorrectionzoo.org/c/homological_cv

Github: https://github.com/errorcorrectionzoo/eczoo_data/tree/main/codes/quantum/oscillators/homological_cv.yml.