# Three qutrit code[1]

## Description

## Protection

Detects single qutrit errors and protects against a single-qutrit erasure. There does not exist a three-qubit code with analogous properties.

The code is an example of a \( ((n = 3, k = 2)) \) threshold scheme where a secret (the quantum information) is split into \( n \) shares and can be reconstructed by \( k \) pieces.

They key property of this code is that the reduced density matrix of any single qutrit is maximally mixed, meaning no information can be extracted from that qutrit. Therefore, a single qutrit tells you nothing about the encoded message, but access to any two pairs of qutrits will reveal the secret.

## Encoding

## Decoding

## Notes

## Parents

- Modular-qudit CSS code — Smallest single-erasure correcting qudit code for \(q>2\).
- Holographic code — Three-qutrit code is a minimal model for holography [2][4].
- Quantum maximum-distance-separable (MDS) code — The three-qutrit code is the smallest nontrivial quantum MDS code.

## Cousins

- Approximate secret-sharing code — Three-qutrit code defines a minimal secret-sharing scheme [1] that is substantially generalized by approximate secret-sharing codes.
- \([[3,1,2]]_{\mathbb Z}\) rotor code

## References

- [1]
- R. Cleve, D. Gottesman, and H.-K. Lo, “How to Share a Quantum Secret”, Physical Review Letters 83, 648 (1999). DOI; quant-ph/9901025
- [2]
- A. Almheiri, X. Dong, and D. Harlow, “Bulk locality and quantum error correction in AdS/CFT”, Journal of High Energy Physics 2015, (2015). DOI; 1411.7041
- [3]
- S. Bravyi and B. Terhal, “A no-go theorem for a two-dimensional self-correcting quantum memory based on stabilizer codes”, New Journal of Physics 11, 043029 (2009). DOI; 0810.1983
- [4]
- D. Harlow, “The Ryu–Takayanagi Formula from Quantum Error Correction”, Communications in Mathematical Physics 354, 865 (2017). DOI; 1607.03901

## Page edit log

- Victor V. Albert (2022-08-12) — most recent
- Felix Huber (2022-08-12)
- Victor V. Albert (2021-12-29)
- Elizabeth R. Bennewitz (2021-12-03)

## Zoo code information

## Cite as:

“Three qutrit code”, The Error Correction Zoo (V. V. Albert & P. Faist, eds.), 2022. https://errorcorrectionzoo.org/c/stab_3_1_2

Github: https://github.com/errorcorrectionzoo/eczoo_data/tree/main/codes/quantum/qudits/stab_3_1_2.yml.