Événements
Séminaire IQ - Lev-Arcady Sellem
Date : 14 Juin 2023 11:00
Type : Institut Quantique
Lieu :
Lieu/Location : Auditorium de l'IQ
Lev-Arcady Sellem
Mines ParisTech, Inria
Invité de Baptiste Royer
Titre/Title
Dissipation engineering for the autonomous stabilization of bosonic quantum error correction codes
Résumé/Abstract
Despite considerable progress over the past decades, noise levels in all physical quantum computing platforms remain far too high to run useful algorithms. Quantum error correction (QEC) would overcome this roadblock by encoding a logical qubit in a high-dimensional physical system and correcting noise-induced evolutions before they accumulate and lead to logical flips.
A major issue for QEC is the huge resource overhead associated with the use of error correcting codes. Bosonic codes aim at reducing this overhead by encoding qubits in exotic states of the infinite-dimensional Hilbert space of a quantum oscillator, instead of a register of finite-dimensional systems. The performance of such bosonic codes thus crucially depends on our ability to stabilize and control these exotic states in presence of noise.
In this talk, I will present a recent proposal for the robust stabilization and control of a qubit encoded using the Gottesman-Kitaev-Preskill (GKP) bosonic code. This scheme relies on the careful engineering of a suitable dissipative bath so that the system naturally relaxes towards GKP states. We obtain analytical results showing that this dissipation scheme provides exponential protection against quadrature noise, and perform extensive numerical simulations to study the effects of more realistic noise models.
I will explain how this dissipative bath could be engineered in the rotating frame of a superconducting Josephson circuit, without opening additional uncontrolled error channels through the coupling to an ancillary system as it is currently the case in all experimental demonstrations of GKP stabilization. We estimate that in a state-of-the-art circuit, this dissipative scheme could allow to witness logical decoherence rates several order of magnitude below the breakeven point given by the lifetime of photons in the bare circuit.
If time allows, I will also briefly mention works in progress on the analysis of generic open quantum systems; on the one hand, numerical studies on the automated computation of problem-specific efficient simulation basis; on the other hand, a recent result on convergence of degenerate dissipative Lindblad equations naturally stemming from dissipation engineering techniques.
Lev-Arcady Sellem
Mines ParisTech, Inria
Invité de Baptiste Royer
Titre/Title
Dissipation engineering for the autonomous stabilization of bosonic quantum error correction codes
Résumé/Abstract
Despite considerable progress over the past decades, noise levels in all physical quantum computing platforms remain far too high to run useful algorithms. Quantum error correction (QEC) would overcome this roadblock by encoding a logical qubit in a high-dimensional physical system and correcting noise-induced evolutions before they accumulate and lead to logical flips.
A major issue for QEC is the huge resource overhead associated with the use of error correcting codes. Bosonic codes aim at reducing this overhead by encoding qubits in exotic states of the infinite-dimensional Hilbert space of a quantum oscillator, instead of a register of finite-dimensional systems. The performance of such bosonic codes thus crucially depends on our ability to stabilize and control these exotic states in presence of noise.
In this talk, I will present a recent proposal for the robust stabilization and control of a qubit encoded using the Gottesman-Kitaev-Preskill (GKP) bosonic code. This scheme relies on the careful engineering of a suitable dissipative bath so that the system naturally relaxes towards GKP states. We obtain analytical results showing that this dissipation scheme provides exponential protection against quadrature noise, and perform extensive numerical simulations to study the effects of more realistic noise models.
I will explain how this dissipative bath could be engineered in the rotating frame of a superconducting Josephson circuit, without opening additional uncontrolled error channels through the coupling to an ancillary system as it is currently the case in all experimental demonstrations of GKP stabilization. We estimate that in a state-of-the-art circuit, this dissipative scheme could allow to witness logical decoherence rates several order of magnitude below the breakeven point given by the lifetime of photons in the bare circuit.
If time allows, I will also briefly mention works in progress on the analysis of generic open quantum systems; on the one hand, numerical studies on the automated computation of problem-specific efficient simulation basis; on the other hand, a recent result on convergence of degenerate dissipative Lindblad equations naturally stemming from dissipation engineering techniques.