ELFT HÍRADÓ

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

Meghívó

BME Elméleti Fizika Szeminárium,

márc. 10. péntek 10h15,

1111 Budapest, Budafoki út 8., BME F III. magasföldszint 01.,
Elméleti Fizika Tanszék szemináriumi szoba

Asbóth János (BME Elm. Fiz. tanszék és Wigner FK Kvantumoptika és
Kvantuminformatika Osztály):
Coherent errors and readout errors in surface code

The surface code is the leading candidate for quantum error correction.
However, the level of protection it offers against coherent errors, i.e.,
nonfluctuating phase rotations on the physical qubits, is not well known.
We consider[1] the combined effect of readout errors and coherent errors on
the surface code. We use a recently developed numerical approach, via a
mapping of the physical qubits to Majorana fermions[2]. We find a threshold
for this combination of errors, with an error rate close to the threshold
of the corresponding incoherent error channel (random Pauli-Z and readout
errors). Below the threshold, scaling up the code leads to the rapid loss
of coherence of errors on the logical level, but error rates that are
greater than those of the corresponding incoherent error channel. We also
vary the coherent and readout error rates independently, and find that the
surface code is more sensitive to coherent errors than to readout errors.
Our work extends the recent results on coherent errors with perfect readout
[2] to the experimentally more realistic situation where readout errors
also occur.

[1]: M Aron and JK Asboth: Coherent errors and readout errors in surface
code,  arXiv:2303.04672
[2]: S Bravyi et al: Correcting coherent errors with surface codes, npj
Quantum Information, vol. 4, no. 55 (2018)

Minden érdeklődőt szeretettel várunk.
Asbóth János,
 szemináriumi koordinátor