Improving Josephson junction reproducibility for superconducting quantum circuits: junction area fluctuation

• URL: http://arxiv.org/abs/2210.15293v1
• Date: Thu, 27 Oct 2022 10:00:24 GMT
• Title: Improving Josephson junction reproducibility for superconducting quantum circuits: junction area fluctuation
• Authors: A.A. Pishchimova, N.S. Smirnov, D.A. Ezenkova, E.A. Krivko, E.V. Zikiy, D.O. Moskalev, A.I. Ivanov, N.D. Korshakov, I.A. Rodionov
• Abstract summary: Josephson superconducting qubits and parametric amplifiers are prominent examples of superconducting quantum circuits. critical current $I_c$ variation of the Josephson junction, as the most important electrical parameter, needs to be minimized. We optimized Josephson junctions fabrication process and demonstrate resistance variation of $9.8-4.4%$ and $4.8-2.3%$ across $22times22$ $mm2$ and $5times10$ $mm2$ chip areas.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Josephson superconducting qubits and parametric amplifiers are prominent examples of superconducting quantum circuits that have shown rapid progress in recent years. With the growing complexity of such devices, the requirements for reproducibility of their electrical properties across a chip have become stricter. Thus, the critical current $I_c$ variation of the Josephson junction, as the most important electrical parameter, needs to be minimized. Critical current, in turn, is related to normal-state resistance the Ambegaokar-Baratoff formula, which can be measured at room temperature. Here, we focus on the dominant source of Josephson junction critical current non-uniformity junction area variation. We optimized Josephson junctions fabrication process and demonstrate resistance variation of $9.8-4.4\%$ and $4.8-2.3\%$ across $22{\times}22$ $mm^2$ and $5{\times}10$ $mm^2$ chip areas, respectively. For a wide range of junction areas from $0.008$ ${\mu}m^2$ to $0.12$ ${\mu}m^2$ we ensure a small linewidth standard deviation of $4$ $nm$ measured over 4500 junctions with linear dimensions from $80$ to $680$ $nm$. The developed process was tested on superconducting highly coherent transmon qubits $(T_1 > 100\:{\mu}s)$ and a nonlinear asymmetric inductive element parametric amplifier.

Related papers

• Quantum dynamics of frustrated Josephson junction arrays embedded in a transmission line: an effective XX spin chain with long-range interaction [0.0]
  We study theoretically a variety of collective quantum phases occurring in frustrated saw-tooth chains of Josephson junctions embedded in a dissipationless transmission line. The direct embedding of $pi$-Josephson junctions in a transmission line allows to establish a short/long-range interaction between (anti)vortices of well separated cells.
  arXiv  Detail & Related papers  (2024-07-04T13:40:08Z)
• Resilience of the quantum critical line in the Schmid transition [0.35342120781147623]
  Schmid predicted that a single Josephson junction coupled to a resistive environment undergoes a quantum phase transition to an insulating phase when the shunt resistance exceeds the resistance quantum $h/(4 e 2)$. Recent measurements and theoretical studies have sparked a debate on whether the location of this transition depends on the ratio between the Josephson and the charging energies. We demonstrate that the transition line between superconducting and insulating behavior is indeed independent of this energy ratio.
  arXiv  Detail & Related papers  (2024-07-01T18:12:51Z)
• Towards large-scale quantum optimization solvers with few qubits [59.63282173947468]
  We introduce a variational quantum solver for optimizations over $m=mathcalO(nk)$ binary variables using only $n$ qubits, with tunable $k>1$. We analytically prove that the specific qubit-efficient encoding brings in a super-polynomial mitigation of barren plateaus as a built-in feature.
  arXiv  Detail & Related papers  (2024-01-17T18:59:38Z)
• Ancilla quantum measurements on interacting chains: Sensitivity of entanglement dynamics to the type and concentration of detectors [46.76612530830571]
  We consider a quantum many-body lattice system that is coupled to ancillary degrees of freedom (detectors'') We explore the dynamics of density and of entanglement entropy in the chain, for various values of $rho_a$ and $M$.
  arXiv  Detail & Related papers  (2023-11-21T21:41:11Z)
• Improving Josephson junction reproducibility for superconducting quantum circuits: shadow evaporation and oxidation [0.0]
  We report on a robust chip scale $Al/AlO_x/Al$ fabrication method due to comprehensive study of shadow evaporation and oxidation steps. We fabricate three $5times10$ $mm2$ chips with 18 transmon qubits showing less than 1.9% frequency variation between qubit on different chips.
  arXiv  Detail & Related papers  (2022-12-13T16:05:43Z)
• Unimon qubit [42.83899285555746]
  Superconducting qubits are one of the most promising candidates to implement quantum computers. Here, we introduce and demonstrate a superconducting-qubit type, the unimon, which combines the desired properties of high non-linearity, full insensitivity to dc charge noise, insensitivity to flux noise, and a simple structure consisting only of a single Josephson junction in a resonator.
  arXiv  Detail & Related papers  (2022-03-11T12:57:43Z)
• Algorithmic Ground-state Cooling of Weakly-Coupled Oscillators using Quantum Logic [52.77024349608834]
  We introduce a novel algorithmic cooling protocol for transferring phonons from poorly- to efficiently-cooled modes. We demonstrate it experimentally by simultaneously bringing two motional modes of a Be$+$-Ar$13+$ mixed Coulomb crystal close to their zero-point energies. We reach the lowest temperature reported for a highly charged ion, with a residual temperature of only $Tlesssim200mathrmmu K$ in each of the two modes.
  arXiv  Detail & Related papers  (2021-02-24T17:46:15Z)
• Simplified Josephson-junction fabrication process for reproducibly high-performance superconducting qubits [0.0]
  Current shadow-evaporation techniques for aluminum-based Josephson junctions require a separate lithography step to deposit a patch. We use one lithography step and one vacuum cycle to evaporate both the junction electrodes and the patch. Such high frequency predictability is a requirement for scaling-up the number of qubits in a quantum computer.
  arXiv  Detail & Related papers  (2020-11-10T16:42:50Z)
• Coherent superconducting qubits from a subtractive junction fabrication process [48.7576911714538]
  Josephson tunnel junctions are the centerpiece of almost any superconducting electronic circuit, including qubits. In recent years, sub-micron scale overlap junctions have started to attract attention. This work paves the way towards a more standardized process flow with advanced materials and growth processes, and constitutes an important step for large scale fabrication of superconducting quantum circuits.
  arXiv  Detail & Related papers  (2020-06-30T14:52:14Z)
• Optimal coupling of HoW$_{10}$ molecular magnets to superconducting circuits near spin clock transitions [85.83811987257297]
  We study the coupling of pure and magnetically diluted crystals of HoW$_10$ magnetic clusters to microwave superconducting coplanar waveguides. Results show that engineering spin-clock states of molecular systems offers a promising strategy to combine sizeable spin-photon interactions with a sufficient isolation from unwanted magnetic noise sources.
  arXiv  Detail & Related papers  (2019-11-18T11:03:06Z)
• Implementation of a transmon qubit using superconducting granular aluminum [0.0]
  grAl may provide a robust source of non-linearity for strongly driven quantum circuits. In intrinsic qubit linewidth $gamma = 2 pi times 10,mathrmkHz$, corresponding to a lifetime of $16,mathrmmu s$. This linewidth remains below $2 pi times 150,mathrmkHz$ for in-plane magnetic fields up to $sim70,mathrmmT$.
  arXiv  Detail & Related papers  (2019-11-06T12:18:43Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.