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Main Authors: Sprave, Isabelle V., Dütz, Denny, Kock, Sebastian, Otten, René, Hangleiter, Tobias, Mende, Felix, Wislicenus, Marcus, Bluhm, Hendrik
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2603.13726
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author Sprave, Isabelle V.
Dütz, Denny
Kock, Sebastian
Otten, René
Hangleiter, Tobias
Mende, Felix
Wislicenus, Marcus
Bluhm, Hendrik
author_facet Sprave, Isabelle V.
Dütz, Denny
Kock, Sebastian
Otten, René
Hangleiter, Tobias
Mende, Felix
Wislicenus, Marcus
Bluhm, Hendrik
contents Scaling solid-state architectures to the millions of qubits required for utility-scale quantum computing could benefit from the integration of control electronics in the immediate vicinity of the quantum layer. However, lithographically fabricated solid-state qubits perform best at temperatures well below 1 K, where available cooling power is limited, whereas the control electronics dissipate substantial power and therefore require the higher cooling power available at elevated temperatures. To address this challenge, we propose a cryopackaging concept that uses broadband phononic Distributed Bragg Reflectors (DBRs) as a thermal barrier between cryoelectronics and the qubit chip. As an experimental realization of this concept, we fabricate and characterize Ta/SiO$_2$ DBR structures. In this architecture, the DBR is intended to provide mechanical support for superconducting vias while offering substantially better thermal insulation than typical bulk materials. For a 600-nm-thick DBR consisting of 10 Ta/SiO$_2$ bilayers, we obtain a thermal conduction below 1 mW/cm$^2$ from 1.5 K to 100 mK. In a centimeter-scale architecture, this level of isolation is compatible with Watt-level cooling power for nearby electronics while maintaining a qubit temperature around 100 mK in commercially available dilution refrigerators.
format Preprint
id arxiv_https___arxiv_org_abs_2603_13726
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Phononic Bragg Reflectors for Thermal Insulation of Scalable Cryogenic Control Electronics from Qubits
Sprave, Isabelle V.
Dütz, Denny
Kock, Sebastian
Otten, René
Hangleiter, Tobias
Mende, Felix
Wislicenus, Marcus
Bluhm, Hendrik
Quantum Physics
Applied Physics
Scaling solid-state architectures to the millions of qubits required for utility-scale quantum computing could benefit from the integration of control electronics in the immediate vicinity of the quantum layer. However, lithographically fabricated solid-state qubits perform best at temperatures well below 1 K, where available cooling power is limited, whereas the control electronics dissipate substantial power and therefore require the higher cooling power available at elevated temperatures. To address this challenge, we propose a cryopackaging concept that uses broadband phononic Distributed Bragg Reflectors (DBRs) as a thermal barrier between cryoelectronics and the qubit chip. As an experimental realization of this concept, we fabricate and characterize Ta/SiO$_2$ DBR structures. In this architecture, the DBR is intended to provide mechanical support for superconducting vias while offering substantially better thermal insulation than typical bulk materials. For a 600-nm-thick DBR consisting of 10 Ta/SiO$_2$ bilayers, we obtain a thermal conduction below 1 mW/cm$^2$ from 1.5 K to 100 mK. In a centimeter-scale architecture, this level of isolation is compatible with Watt-level cooling power for nearby electronics while maintaining a qubit temperature around 100 mK in commercially available dilution refrigerators.
title Phononic Bragg Reflectors for Thermal Insulation of Scalable Cryogenic Control Electronics from Qubits
topic Quantum Physics
Applied Physics
url https://arxiv.org/abs/2603.13726