Saved in:
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2405.11375 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866914157313392640 |
|---|---|
| author | Bhandari, Bibek Huang, Irwin Hajr, Ahmed Yanik, Kagan Qing, Bingcheng Wang, Ke Santiago, David I Dressel, Justin Siddiqi, Irfan Jordan, Andrew N |
| author_facet | Bhandari, Bibek Huang, Irwin Hajr, Ahmed Yanik, Kagan Qing, Bingcheng Wang, Ke Santiago, David I Dressel, Justin Siddiqi, Irfan Jordan, Andrew N |
| contents | We theoretically explore an alternative circuit for Kerr-cat qubits based on symmetrically threaded Superconducting Quantum Interference Devices (SQUID). The Symmetrically Threaded SQUIDs (STS) architecture employs a simplified flux-pumped design that suppresses two-photon dissipation, a dominant loss mechanism in high-Kerr regimes, by engineering the drive Hamiltonian's flux operator to generate only even-order harmonics. By fulfilling two critical criteria for practical Kerr-cat qubit operation, the STS emerges as an ideal platform: (1) a static Hamiltonian with diluted Kerr nonlinearity (achieved via the STS's middle branch) and (2) a drive Hamiltonian restricted to even harmonics, which ensures robust two-photon driving with reduced dissipation. For weak Kerr nonlinearity, we find that the coherent state lifetime ($T_α$) is similar between STS and SNAIL circuits. However, STS Kerr-cat qubits exhibit enhanced resistance to higher-order photon dissipation, enabling significantly extended $T_α$ even with stronger Kerr nonlinearities ($\sim$10 MHz). In contrast to SNAIL, STS Kerr-cat qubits display a $T_α$ dip under weak two-photon driving for high Kerr coefficient. We demonstrate that this dip can be suppressed by applying drive-dependent detuning, enabling Kerr-cat qubit operation with only eight Josephson junctions (of energies 80 GHz); fewer junctions suffice for higher junction energies. We further validate the robustness of the STS design by studying the impact of strong flux driving and asymmetric Josephson junctions on $T_α$. With the proposed design and considering a cat size of 10 photons, we predict $T_α$ of the order of tens of milliseconds, even in the presence of multi-photon heating and dephasing effects. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2405_11375 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Symmetrically Threaded Superconducting Quantum Interference Devices As Next Generation Kerr-cat Qubits Bhandari, Bibek Huang, Irwin Hajr, Ahmed Yanik, Kagan Qing, Bingcheng Wang, Ke Santiago, David I Dressel, Justin Siddiqi, Irfan Jordan, Andrew N Quantum Physics We theoretically explore an alternative circuit for Kerr-cat qubits based on symmetrically threaded Superconducting Quantum Interference Devices (SQUID). The Symmetrically Threaded SQUIDs (STS) architecture employs a simplified flux-pumped design that suppresses two-photon dissipation, a dominant loss mechanism in high-Kerr regimes, by engineering the drive Hamiltonian's flux operator to generate only even-order harmonics. By fulfilling two critical criteria for practical Kerr-cat qubit operation, the STS emerges as an ideal platform: (1) a static Hamiltonian with diluted Kerr nonlinearity (achieved via the STS's middle branch) and (2) a drive Hamiltonian restricted to even harmonics, which ensures robust two-photon driving with reduced dissipation. For weak Kerr nonlinearity, we find that the coherent state lifetime ($T_α$) is similar between STS and SNAIL circuits. However, STS Kerr-cat qubits exhibit enhanced resistance to higher-order photon dissipation, enabling significantly extended $T_α$ even with stronger Kerr nonlinearities ($\sim$10 MHz). In contrast to SNAIL, STS Kerr-cat qubits display a $T_α$ dip under weak two-photon driving for high Kerr coefficient. We demonstrate that this dip can be suppressed by applying drive-dependent detuning, enabling Kerr-cat qubit operation with only eight Josephson junctions (of energies 80 GHz); fewer junctions suffice for higher junction energies. We further validate the robustness of the STS design by studying the impact of strong flux driving and asymmetric Josephson junctions on $T_α$. With the proposed design and considering a cat size of 10 photons, we predict $T_α$ of the order of tens of milliseconds, even in the presence of multi-photon heating and dephasing effects. |
| title | Symmetrically Threaded Superconducting Quantum Interference Devices As Next Generation Kerr-cat Qubits |
| topic | Quantum Physics |
| url | https://arxiv.org/abs/2405.11375 |