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arxiv: 2606.00446 · v1 · pith:HF6AJD2Znew · submitted 2026-05-30 · ❄️ cond-mat.mes-hall · quant-ph

Individually tunable Si/SiGe quantum dot operating voltages via gate-biased illumination

Jared Benson , Sanghyeok Park , Owen M. Eskandari , M. A. Wolfe , Brighton X. Coe , J. P. Dodson , S. N. Coppersmith , Mark Friesen
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M. A. Eriksson
This is my paper

Pith reviewed 2026-06-28 18:41 UTC · model grok-4.3

classification ❄️ cond-mat.mes-hall quant-ph
keywords Si/SiGe quantum dotsoperating voltage tuninggate-biased illuminationtrapped charge distributioncharge noisetriple quantum dotnear-infrared light
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The pith

Gate-biased near-infrared illumination shifts trapped charges to tune each quantum dot's operating voltage independently.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper presents a method that uses near-infrared light applied while gate voltages are held to controllably alter the distribution of trapped charges at the oxide-semiconductor interface. This shift changes the voltage needed on each gate to reach the desired operating point, allowing the voltages to be made more uniform across a device. The approach is demonstrated on a Si/SiGe quantum dot device and extended to a triple-dot array tuned into the (1,1,1) configuration. A reader would care because typical quantum dot devices require widely different voltages on neighboring gates, and a gate-selective, repeatable correction could simplify tuning while leaving charge noise unchanged.

Core claim

Illumination with near-infrared light while gate voltages are applied produces a controllable, repeatable, and gate-selective shift in the nanoscale trapped charge distribution at the oxide-semiconductor interface; this shift moves the operating voltages of individual gates without changing measured charge noise, as shown by tuning a triple quantum dot to uniform small voltages in the (1,1,1) state.

What carries the argument

Gate-biased illumination that modifies the trapped charge distribution at the interface to adjust each gate's effective potential.

If this is right

  • Operating voltages on separate gates can be adjusted individually and made more uniform.
  • The same illumination protocol can be applied gate-by-gate to reach a target charge configuration such as (1,1,1) with smaller voltages.
  • Charge noise spectra remain unchanged after the voltage shifts are performed.
  • Self-consistent Schrödinger-Poisson simulations reproduce the observed voltage shifts from redistribution of interface charge.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The same protocol might reduce the spread of operating voltages in larger linear or 2D arrays of dots.
  • If the charge redistribution is stable over time, periodic recalibration with light could maintain uniformity without continuous voltage adjustments.
  • The method may extend to other semiconductor-oxide systems where interface traps limit voltage uniformity.

Load-bearing premise

Illumination with near-infrared light while gate voltages are applied produces a controllable, repeatable, and selective shift in trapped charge without adding new noise sources or instability.

What would settle it

Repeated illumination cycles under different gate bias patterns produce no distinguishable shifts in the measured operating voltages, or charge noise increases after the illumination step.

Figures

Figures reproduced from arXiv: 2606.00446 by Brighton X. Coe, Jared Benson, J. P. Dodson, M. A. Eriksson, Mark Friesen, M. A. Wolfe, Owen M. Eskandari, Sanghyeok Park, S. N. Coppersmith.

Figure 1
Figure 1. Figure 1: Gate-biased illumination enables low-voltage operation of quantum dots. [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Characterizing gate-biased illumination by simulating and measuring gate pinch-off voltage shifts. [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Experimental (diamonds) and simulated (circles) shifts in pinch-off voltages showing good agreement for [PITH_FULL_IMAGE:figures/full_fig_p005_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Charge noise comparison between a typical operating regime and a low-voltage operating regime. [PITH_FULL_IMAGE:figures/full_fig_p006_4.png] view at source ↗
read the original abstract

Semiconductor quantum dot qubits often require very different voltages on each gate to bring them to a correct operating point. Here, we present a method by which one can controllably and repeatably alter the nanoscale trapped charge distribution at an oxide-semiconductor interface. We demonstrate this method on a Si/SiGe quantum dot device, and we find that the operating voltages can be controlled and made much more uniform. The method relies on illumination with near-infrared light in the presence of applied gate voltages, and it enables the tuning of the device operating point on a gate-by-gate basis. We present an explanation of the underlying physics using self-consistent Schr\"odinger-Poisson simulations. As an application of this method, we tune a triple quantum dot to have uniform and small operating voltages in the (1,1,1) charge configuration. Importantly, we show that shifting the operating voltages in this way does not change the measured charge noise.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The paper introduces a method to individually tune the operating voltages of gates in Si/SiGe quantum dot devices by illuminating with near-infrared light while applying gate biases. This modifies the trapped charge at the interface in a controllable way. The authors demonstrate the method on a triple quantum dot device, achieving uniform small operating voltages in the (1,1,1) charge state, supported by Schrödinger-Poisson simulations. They also show that this tuning does not affect the measured charge noise.

Significance. This technique could be significant for scaling up semiconductor-based quantum dot qubits by simplifying the tuning process for multi-dot systems. The ability to make operating voltages more uniform without increasing noise is a valuable contribution if the results are robust. The simulations help explain the underlying mechanism involving charge redistribution.

major comments (2)
  1. [Experimental demonstration] The claim that charge noise is unchanged after the illumination procedure is central to the application. The manuscript should specify the measurement conditions, number of repetitions, and any statistical analysis used to conclude that the noise is unaffected (e.g., in the section describing the (1,1,1) configuration tuning).
  2. [Simulations] The Schrödinger-Poisson simulations are used to explain the physics. It would strengthen the paper to compare the simulated voltage shifts quantitatively with the experimental observations to validate the model.
minor comments (2)
  1. Ensure that all figures have clear labels and captions that allow the reader to understand the data without referring to the main text.
  2. The abstract mentions 'much more uniform'; consider providing quantitative metrics for the uniformity improvement in the main text.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their positive assessment and constructive comments on our manuscript. We address each major comment below and will incorporate revisions to strengthen the paper.

read point-by-point responses

  1. Referee: [Experimental demonstration] The claim that charge noise is unchanged after the illumination procedure is central to the application. The manuscript should specify the measurement conditions, number of repetitions, and any statistical analysis used to conclude that the noise is unaffected (e.g., in the section describing the (1,1,1) configuration tuning).

    Authors: We agree that additional details on the noise measurements will improve clarity. In the revised manuscript, we will expand the relevant section to specify the measurement conditions (including bias points and temperature), the number of repetitions performed, and the statistical analysis (e.g., standard deviation across traces) used to conclude that charge noise is unaffected. revision: yes

  2. Referee: [Simulations] The Schrödinger-Poisson simulations are used to explain the physics. It would strengthen the paper to compare the simulated voltage shifts quantitatively with the experimental observations to validate the model.

    Authors: We thank the referee for this suggestion. The current simulations provide a qualitative explanation of the charge redistribution mechanism. In the revision, we will add a quantitative comparison between the simulated gate voltage shifts and the experimentally observed shifts for the tuned gates, including a table or plot of the values to validate the model. revision: yes

Circularity Check

0 steps flagged

No significant circularity identified

full rationale

The paper reports an experimental demonstration of gate-biased near-IR illumination to controllably shift interface trapped charge and thereby tune quantum-dot operating voltages on a per-gate basis. The central results (uniform (1,1,1) operating points in a triple-dot device, unchanged charge noise) are presented as direct measurements rather than as outputs of any derivation chain. Schrödinger-Poisson simulations are invoked only for mechanistic explanation, not as a predictive model whose parameters are fitted to the target data. No equations, fitted-input predictions, self-citation load-bearing steps, or ansatz smuggling appear in the reported argument. The work is therefore self-contained against external experimental benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

Ledger populated from abstract only; no free parameters or invented entities are described. The sole domain assumption is that Schrödinger-Poisson modeling captures the light-induced charge movement.

axioms (1)
  • domain assumption Self-consistent Schrödinger-Poisson simulations accurately capture the physics of light-induced trapped charge redistribution at the oxide-semiconductor interface.
    Invoked to explain the underlying mechanism of the tuning effect.

pith-pipeline@v0.9.1-grok · 5733 in / 1278 out tokens · 20186 ms · 2026-06-28T18:41:05.535989+00:00 · methodology

discussion (0)

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Reference graph

Works this paper leans on

12 extracted references · 12 canonical work pages

  1. [1]

    Single- electron operations in a foundry-fabricated array of quantum dots.Nat

    (1) Ansaloni, F.; Chatterjee, A.; Bohuslavskyi, H.; Bertrand, B.; Hutin, L.; Vinet, M.; Kuemmeth, F. Single- electron operations in a foundry-fabricated array of quantum dots.Nat. Commun.2020,11, 6399, DOI: 10.1038/s41467-020-20280-3. (2) Zwerver, A. M. J. et al. Qubits made by advanced semiconductor manufacturing.Nat. Electron.2022,5, 184–190, DOI:10.103...

    work page doi:10.1038/s41467-020-20280-3 2020

  2. [2]

    C.; Manfra, M

    Gardner, G. C.; Manfra, M. J.; Reilly, D. J. A cryogenic CMOS chip for generating control signals for multiple qubits.Nat. Electron.2021,4, 64–70, DOI:10.1038/s41928-020-00528-y. (10) Park, J.-S. et al. 13.1 A fully integrated cryo-CMOS SoC for qubit control in quantum computers capable of state manipulation, readout and high-speed gate pulsing of spin qu...

    work page doi:10.1038/s41928-020-00528-y 2021

  3. [3]

    Memristor-based cryogenic programmable DC sources for scalable in situ quantum-dot control.IEEE Trans

    Alibart, F.; Pioro-Ladrière, M.; Drouin, D. Memristor-based cryogenic programmable DC sources for scalable in situ quantum-dot control.IEEE Trans. Electron Devices2023,70, 1989–1995, DOI:10.1109/ted.2023. 3244133. (12) Schreckenberg, L.; Otten, R.; Vliex, P.; Xue, R.; Tu, J.-S.; Seidler, I.; Trellenkamp, S.; Schreiber, L. R.; Bluhm, H.; van Waasen, S. SiG...

    work page doi:10.1109/ted.2023 1989

  4. [4]

    J.; Dzurak, A

    Voinigescu, S.; Reilly, D. J.; Dzurak, A. S. CMOS compatibility of semiconductor spin qubits.Nat. Rev. Electr. Eng.2026,3, 300–315, DOI:10.1038/s44287-026-00283-w. (15) Vandersypen, L. M. K.; Bluhm, H.; Clarke, J. S.; Dzurak, A. S.; Ishihara, R.; Morello, A.; Reilly, D. J

    work page doi:10.1038/s44287-026-00283-w 2026

  5. [5]

    R.; Veldhorst, M

    Schreiber, L. R.; Veldhorst, M. Interfacing spin qubits in quantum dots and donors–hot, dense, and coherent. Npj Quantum Inf.2017,3, 1–10, DOI:10.1038/s41534-017-0038-y. (16) Veldhorst, M.; Eenink, H. G. J.; Yang, C. H.; Dzurak, A. S. Silicon CMOS architecture for a spin-based quantum computer.Nat. Commun.2017,8, 1766, DOI:10.1038/s41467-017-01905-6. (17)...

    work page doi:10.1038/s41534-017-0038-y 2017

  6. [6]

    R.; Bluhm, H

    Otten, R.; Seidler, I.; Xue, R.; Schreiber, L. R.; Bluhm, H. The SpinBus architecture for scaling spin qubits with electron shuttling.Nat. Commun.2024,15, 4977, DOI:10.1038/s41467-024-49182-4. (18) Meyer, M.; Déprez, C.; van Abswoude, T. R.; Meijer, I. N.; Liu, D.; Wang, C.-A.; Karwal, S.; Oosterhout, S

    work page doi:10.1038/s41467-024-49182-4 2024

  7. [7]

    W.; Scappucci, G.; Veldhorst, M

    Borsoi, F.; Sammak, A.; Hendrickx, N. W.; Scappucci, G.; Veldhorst, M. Electrical control of uniformity in quantum dot devices.Nano Lett.2023,23, 2522–2529, DOI:10.1021/acs.nanolett.2c04446. 11 (19) Meyer, M.; Déprez, C.; Meijer, I. N.; Unseld, F. K.; Karwal, S.; Sammak, A.; Scappucci, G.; Vandersypen, L. M. K.; Veldhorst, M. Single-electron occupation in...

    work page doi:10.1021/acs.nanolett.2c04446 2023

  8. [8]

    Collard, P.; Salis, G.; Fuhrer, A.; Hendrickx, N. W. Impact of interface traps on charge noise and low-density transport properties in Ge/SiGe heterostructures.Commun. Mater.2024,5, 151, DOI:10.1038/s43246- 024-00563-8. (21) Ferrero, J.; Koch, T.; Vogel, S.; Schroller, D.; Adam, V.; Xue, R.; Seidler, I.; Schreiber, L. R.; Bluhm, H

    work page doi:10.1038/s43246- 2024

  9. [9]

    Noise reduction by bias cooling in gated Si/SixGe1−xquantum dots.Appl

    Wernsdorfer, W. Noise reduction by bias cooling in gated Si/SixGe1−xquantum dots.Appl. Phys. Lett.2024, 124, 204002, DOI:10.1063/5.0206632. (22) Diebel, L. K.; Zinkl, L. G.; Hötzinger, A.; Reichmann, F.; Lisker, M.; Yamamoto, Y.; Bougeard, D. Impact of biased cooling on the operation of undoped silicon quantum well field-effect devices.AIP Adv.2025,15, 03...

    work page doi:10.1063/5.0206632 2024

  10. [10]

    F.; Coppersmith, S

    Edge, L. F.; Coppersmith, S. N.; Eriksson, M. A. Fabrication process and failure analysis for robust quantum dots in silicon.Nanotechnology2020,31, 505001, DOI:10.1088/1361-6528/abb559. (26) Saku, T. S. T.; Muraki, K. M. K.; Hirayama, Y. H. Y. High-Mobility Two-Dimensional Electron Gas in an Undoped Heterostructure: Mobility Enhancement after Illumination...

    work page doi:10.1088/1361-6528/abb559 1998

  11. [11]

    Quantum repeaters based on concatenated bosonic and discrete-variable quantum codes,

    Mongillo, M.; Wan, D.; Govoreanu, B.; Radu, I. P.; Li, R.; Van Dorpe, P.; De Greve, K. Low charge noise quantum dots with industrial CMOS manufacturing.NPJ Quantum Inf.2024,10, 70, DOI:10.1038/s41534- 024-00864-3. (33) Connors, E. J.; Nelson, J. J.; Qiao, H.; Edge, L. F.; Nichol, J. M. Low-frequency charge noise in Si/SiGe quantum dots.Phys. Rev. B.2019,1...

    work page doi:10.1038/s41534- 2024

  12. [12]

    A.; Zwolak, J

    Friesen, M.; Eriksson, M. A.; Zwolak, J. P. Bootstrapping, autonomous testing, and initialization system for Si/SixGe1−x multi-quantum-dot devices.Phys. Rev. Appl.2026,25, 014043, DOI:10.1103/vbtg-fws9. (35) Bian, X.; Briggs, G. A. D.; Mol, J. A. Parallel refreshed cryogenic charge-locking array with low power dissi- pation.arXiv [quant-ph]2024, DOI:10.48...

    work page doi:10.1103/vbtg-fws9 2026