ELFT HÍRADÓ

[Janos Asboth <asboth.janos AT ttk.bme.hu>]

Meghívó

BME Elméleti Fizika Szeminárium,

máj. 9 péntek 10h15,
1111 Bp., Budafoki út 8., BME FIII. magasföldszint 1, szemináriumi szoba

Domokos Bálint (BME fizikus MSc):
Characterization of errors in a CNOT between surface code patches

As current experiments already realize small quantum circuits on error
corrected qubits, it is important to fully understand the effect of
physical errors on the logical error channels of these fault-tolerant
circuits. Here[1], we investigate a lattice-surgery-based CNOT operation
between two surface code patches under phenomenological error models. (i)
For two-qubit logical Pauli measurements – the elementary building block of
the CNOT – we optimize the number of stabilizer measurement rounds, usually
taken equal to d, the size (code distance) of each patch. We find that the
optimal number can be greater or smaller than d, depending on the rate of
physical and readout errors, and the separation between the code patches.
(ii) We fully characterize the two-qubit logical error channel of the
lattice-surgery-based CNOT. We find a symmetry of the CNOT protocol, that
results in a symmetry of the logical error channel. We also find that
correlations between X and Z errors on the logical level are suppressed
under minimum weight decoding.

[1] Bálint Domokos, Áron Márton, and János K. Asbóth. "Characterization of
errors in a CNOT between surface code patches." Quantum 8 (2024): 1577

Minden érdeklődőt szeretettel várunk.
Asbóth János,
 szemináriumi koordinátor