Transmon-assisted high-fidelity controlled-Z gates for integer fluxonium qubits

H. Xiong; H.-Y. Zhang; J.-H. Wang; J.-Z. Yang; L.-M. Duan; Y.-P. Song

REVIEW 3 major objections 7 minor 63 references

Transmon-assisted high-fidelity controlled-Z gates for integer fluxonium qubits

T0 review · 3 major / 7 minor · reviewed 2026-08-15 · deepseek-v4-flash

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Pith's one-line read Using a transmon coupler between two integer fluxonium qubits, this paper proposes two controlled-Z gate schemes—one flux-activated and one microwave-activated—that reach coherent errors around 1e-6 within tens of nanoseconds.

desk verdict A genuinely new two-qubit gate proposal for integer fluxoniums with careful numerics, but the headline 1e-6 coherent error is not yet a device target without a sensitivity analysis. read the letter →

arxiv 2509.04776 v1 pith:T3E4FRTF submitted 2025-09-05 quant-ph

J.-H. Wang , H. Xiong , J.-Z. Yang , H.-Y. Zhang , Y.-P. Song , L.-M. Duan This is my paper · ORCID

classification quant-ph PACS 03.67.Lx85.25.Cp

keywords integerfluxoniumqubittransmoncouplercontrolled-ZgateZZinteractionsuppressionadiabaticfluxpulsemicrowave-activatednoisesuperconductingarchitecture

verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

This paper proposes a route to high-fidelity two-qubit gates for integer fluxoniums, a protected superconducting qubit that has so far demonstrated single-qubit control but no entangling gates. The authors argue that coupling two integer fluxoniums through a tunable transmon coupler can completely cancel the always-on ZZ coupling between the qubits at the idling point, and that the same coupler can implement two different controlled-Z gates: a flux-pulse adiabatic gate and a microwave-activated non-adiabatic gate. In simulation, both schemes reach coherent errors around $10^{-6}$ within roughly 50 to 70 ns, and after including relaxation and $1/f$ flux noise the estimated total error stays near $10^{-4}$, suggesting 99.99% CZ fidelities are within reach for current coherence times. The same architecture also extends to a hybrid integer-fluxonium/conventional-fluxonium system, which broadens the frequency range available for scalable processors.

What carries the argument

The load-bearing objects are the leakage-rate factors $D_{ij}$ defined in Eq. (5), which measure how strongly each computational state couples to all other eigenstates during a flux ramp; the pulse edge is shaped so that the flux velocity is inversely proportional to the summed factor, giving a constant leakage rate, and the flat duration is then tuned so residual leaked populations interfere destructively at the end. For the static coupling, the ZZ strength is decomposed into second-, third-, and fourth-order perturbative terms, and the coupler parameters are chosen so these terms cancel. For the microwave gate, the machinery is the repulsion of the coupler's first excited state by the fluxoniums' third excited states, which creates a selective drive target, plus a drive detuning that compensates the ac-Stark phase deviations.

What would settle it

Fabricate an FTF pair with the paper's quoted parameters, measure the static ZZ at the predicted cancellation flux, and run the designed 70 ns adiabatic pulse; if the residual ZZ is not near zero or the leakage error exceeds $10^{-6}$ by more than a small factor under calibrated control, the central claim fails.

Watch

Extended reading notes

Core claim

Working at zero external flux, two integer fluxoniums coupled through a transmon coupler can have their static ZZ coupling eliminated by destructive interference among second-, third-, and fourth-order perturbative contributions, while the computational states remain only weakly hybridized. The paper then claims two coupler-control CZ schemes: an adiabatic scheme in which a flux pulse with a constant-leakage-rate edge and an optimized flat plateau accumulates the conditional $\pi$ phase, reaching coherent errors below $10^{-4}$, $10^{-5}$, and $10^{-6}$ for gate durations under 40, 50, and 70 ns respectively; and a microwave-activated scheme in which driving the coupler's 0-1 transition through a full Rabi cycle acquires a geometric phase, with the coupler level repelled by the fluxoniums' third excited states, reaching $10^{-5}$ error at 50 ns and lower at longer durations. Both schemes keep the coupler as the only driven element, and with relaxation and flux noise taken into account the paper estimates total CZ errors at the $10^{-4}$ level, projecting fidelities above 99.99% for qubit $T_1$ above 500 microseconds.

Load-bearing premise

The headline coherent-error numbers assume the real circuit matches the model Hamiltonian, so the precomputed constant-leakage-rate pulse stays optimal; the authors state that fabrication parameter spread and flux-line waveform distortion will inevitably disturb this pulse.

Editorial extensions

If this is right

If the simulated errors hold, integer fluxonium qubits can be entangled with CZ fidelities above 99.99%, matching or exceeding current transmon two-qubit gates.
The static ZZ cancellation works across a range of coupling strengths, so idling qubits in a multi-qubit array can be left coupled without a residual always-on error.
The adiabatic scheme's flat-duration optimization cuts leakage by up to about three orders of magnitude over a fixed-edge pulse, so pulse shaping alone can close most of the coherent-error budget.
The microwave scheme's single charge line on the coupler removes the need for simultaneous drives on both data qubits, reducing crosstalk and calibration overhead in scaled-up circuits.
In the hybrid IF-T-F system, both gate families remain viable with redesigned spectra, allowing integer and conventional fluxoniums to coexist in one processor without frequency crowding.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

The constant-leakage-rate edge construction depends only on the $D_{ij}$ factors and the ZZ curve, so it should transfer to other tunable-coupler architectures whose level structure is not transmon-like, provided those factors are measured or modelled.
The perturbative cancellation picture suggests a design rule: fix the qubit-coupler and direct qubit-qubit capacitances so the second-, third-, and fourth-order ZZ contributions interfere destructively, which could be used to engineer ZZ-free idling in larger lattices.
The microwave scheme's 99.99% projection relies on the fluxonium third-excited states having useful coherence, which the paper notes is experimentally uncharacterized; a short |3>-state lifetime would tighten the achievable fidelity bound.
A natural next step is to calibrate the pulse edge derived from $D_{ij}$ experimentally on a single FTF pair and compare the measured leakage against the predicted curve; agreement would validate using the same method for spectator-heavy multi-qubit circuits.

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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Desk Editor's Note

read the letter

The genuinely new bit here is that two-qubit gates for integer fluxoniums have been missing from the literature, and this paper fills the gap with two concrete schemes: a flux-activated adiabatic CZ gate and a microwave-activated non-adiabatic CZ gate, both using a transmon coupler. The ZZ-cancellation analysis is clean, the use of the constant-leakage-rate pulse edge and flat-duration interference is well motivated, and the error budget includes T1 and quasistatic flux noise. The simulations look careful, and they shared the code. That is real evidence of a solid working proposal, not a sketch.

Where the paper is soft is exactly where the reader and stress-test put their fingers. The adiabatic gate's 1e-6 coherent error depends on knowing every matrix element in the Hamiltonian to design the pulse edge, and the flat-duration suppression works by interfering leakage amplitudes. The authors themselves say parameter variations and waveform distortion are unavoidable and calibration is out of scope, but they do not quantify how the error degrades under fabrication mistargeting or pulse distortion. That is a load-bearing premise, and the lack of sensitivity analysis means the headline number should be read as a best-case simulation, not a robustness claim. The microwave scheme also leans on the |3> state coherence of the fluxonium, which they correctly flag as experimentally unexplored. The more realistic total error of around 1e-4, once decoherence is folded in, is stated honestly, so this is not a case of overclaiming: the abstract's 1e-6 is clearly labeled as coherent error in an ideal model.

The spectator-qubit analysis in Appendix D is a nice attempt to probe robustness, and the reduced-coupling benchmark in Fig. 9 goes in the right direction, but neither replaces a proper parameter-variation study. That said, the central physics holds up: the FTF architecture can suppress static ZZ, the two gate schemes are distinct and plausible, and the limitations are stated rather than hidden. A serious referee could push for a sensitivity analysis and a more careful statement of what the quoted fidelities assume.

Who is this for? Mostly superconducting-circuit theorists and experimentalists working on fluxonium processors, especially anyone wondering whether integer fluxoniums can be used for entangling gates. I think it deserves a real peer review, not a desk rejection. If I were refereeing, I would ask for the robustness analysis before accepting the headline numbers as device targets, but the work itself is honest and useful.

Referee Report

3 major / 7 minor

Summary. This paper proposes two controlled-Z gate schemes for a fluxonium-transmon-fluxonium (FTF) architecture in which both fluxoniums are integer fluxoniums operated at zero flux bias. The authors first show that the static ZZ interaction can be cancelled by a suitable choice of coupler parameters, and then design two gates: a flux-activated adiabatic CZ gate whose pulse edges maintain a constant leakage rate and whose flat duration is optimized for destructive interference of residual leakage, and a microwave-activated CZ gate driven through the coupler charge line that exploits level repulsion between the coupler and the fluxonium third-excited states. For the adiabatic gate, coherent errors below 1e-4, 1e-5, and 1e-6 are reported for gate durations below about 40, 50, and 70 ns, respectively; for the microwave gate, coherent errors of 1e-5, 1e-6, and 1e-7 are reported at 50, 70, and 100 ns. The authors include T1 dissipation and quasistatic 1/f flux noise in their error budgets and argue that CZ fidelities above 99.99% are feasible if the qubit T1 is around 500 microseconds. A hybrid integer-fluxonium/conventional-fluxonium system is also discussed qualitatively. The numerical work uses scqubits and QuTiP, and the simulation code is shared on GitHub.

Significance. If the reported error levels are robust, this is a useful proposal for entangling gates in a relatively new qubit platform: it extends the transmon-coupler toolbox to integer fluxoniums, demonstrates static-ZZ cancellation with small delocalization, and reduces crosstalk by using a dedicated coupler line for the microwave gate. The paper also provides a detailed capacitance-matrix analysis for scalable 1D and 2D architectures, and the availability of the simulation code is a strength. The central results are numerical predictions for specified circuit Hamiltonians rather than fits to external data, so they are not circular by construction. However, the headline coherent-error numbers are obtained for the nominal Hamiltonian and optimized pulse parameters, and the robustness of these numbers to parameter uncertainty and waveform distortion is not quantified; this is the main risk to the central claims.

major comments (3)

[Sec. III B and III C] The coherent-error numbers for the adiabatic CZ gate (below 1e-4, 1e-5, and 1e-6 for gate durations below about 40, 50, and 70 ns in Fig. 3(a)) are computed for the nominal Hamiltonian only. The constant-leakage-rate pulse edge is constructed from the D_ij functions in Eqs. (5)-(6), which require quantitative knowledge of all matrix elements and level spacings, and the flat-duration optimization suppresses leakage by destructive interference of the residual leakage amplitudes from the two edges (Fig. 9(a) and Appendix C 1). The authors state in Sec. III C that parameter variations are almost inevitable and waveform distortion is unavoidable, and that experimental calibration of the edge shape is outside the scope. No sensitivity analysis is provided for typical fabrication spreads in E_J, E_C, E_L, J_c, or J_12, nor for finite-bandwidth distortion of the flux pulse. Since the reported 1e-5 and 1e-6 levels are below the scale at which such imperfections will dominate, the headline claim is not yet supported for a physical device. I request a robustness scan that quantifies the tolerable parameter deviations, or a clear rephrasing of these numbers as ideal-model results.
[Sec. IV C and Appendix D] The microwave-activated gate has the same model-exactness limitation. The coherent errors of 1e-5 at 50 ns, 1e-6 at 70 ns, and 1e-7 at 100 ns (Fig. 5(a)) are obtained after optimizing both the drive frequency and the drive amplitude for a specific set of energy levels and matrix elements. The only sensitivity study reported (Appendix D, Fig. 11(d)) concerns a spectator-induced 0.15 MHz shift of the coupler frequency; it does not cover fabrication uncertainty in E_J,c, E_C,c, or in the fluxonium |3>-state frequencies that produce the level repulsion. Because the authors propose that a fixed-frequency transmon is feasible, the required frequency and parameter precision must be quantified. I recommend adding an offset-sensitivity analysis, for example gate error versus target-transition-frequency offset, or explicitly stating the precision requirement.
[Appendix C 2 and Sec. III C] The quasistatic flux-noise error estimate used to obtain the total-error level near 1e-4 is computed by assigning a static flux offset with variance sigma_phi^2 = integral of A_phi^2/f over f_IR = 1e-6 Hz to f_UV = 1 GHz. This is internally inconsistent with the quasistatic assumption: noise components with frequencies comparable to or larger than the gate rate are not static on the gate timescale, and extending the integral to 1 GHz is not justified. The resulting estimate should be presented as a rough order-of-magnitude model, with a cut-off choice limited to frequencies below roughly 1/T_g or with an explicit justification of the chosen band. The authors' caveat in Sec. VI that the noise spectrum may differ in experiment partially mitigates this concern, but as written the 1e-4 bound is not derived from a well-defined noise model.

minor comments (7)

[Sec. IV D] The heading 'Comparision' should be 'Comparison'.
[Sec. III C] The sentence 'the quasi-static flux-noise-induced error can reach below x10^{-4}' appears to be missing a leading factor; it should read 'below 1x10^{-4}'.
[Sec. IV B] The statement that the pulse amplitude is set to 1/(A N_T) to achieve a 2pi rotation is dimensionally incomplete; a 2pi pulse requires integral of epsilon(t) N_T dt = 2pi, so either the definition of A or the formula should include the 2pi factor, or the normalization should be clarified.
[Abstract and Sec. IV C] The 1e-6 coherent error for the microwave gate is achieved at 70 ns duration, not at 50 ns; the phrase 'several tens of nanoseconds' is defensible but should be tied to the simulated durations to avoid overstatement.
[Appendix C 2] The definition sigma_phi = sqrt(<delta_phi_ext,c>) should be sigma_phi^2 = <delta_phi_ext,c^2>, i.e., sigma_phi = sqrt(<delta_phi_ext,c^2>).
[Sec. VI] The conclusion cites transmon T1 values above 100 microseconds (Ref. [52]) to support the feasibility of a 99.99% CZ gate, but the simulations require fluxonium T1 around 500 microseconds; this argument should be rephrased or supported by fluxonium coherence data.
[Throughout] Flux bias is written in inconsistent forms, for example 'phi_ext,c/2pi = 0.21' and 'phi_ext,c = 0.22 x 2pi'; please use a single convention consistently.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the gate-error numbers are outputs of explicit numerical simulations of the stated circuit Hamiltonian, not fits dressed as predictions.

full rationale

The headline coherent errors for both CZ schemes are outputs of numerical time evolution of the explicit FTF Hamiltonian (Eq. 1) for concrete circuit parameters. The adiabatic pulse is generated by the constant-leakage-rate heuristic based on the D factors of Eq. (5) and the ramp constraint of Eq. (6), and the flat duration is then optimized by sweeping it against the simulated leakage; the reported 10^-4 / 10^-5 / 10^-6 errors are simulation outputs, not inputs. The microwave-activated scheme similarly uses the S parameters of Eqs. (8)-(9) only as a design filter, and the final fidelities are obtained by full master-equation simulation after optimizing drive frequency and amplitude. No parameter is fitted to an external data set and then renamed a prediction, and no target result is defined in terms of itself. The ZZ-suppression claim is checked by direct numerical diagonalization after a perturbation-theory design (Appendix B), which is a standard design loop rather than a circular derivation. Self-citations such as Refs. [9,42] appear only in broad contextual citation ranges and are not load-bearing. The paper even flags in Sec. III C that the constant-leakage-rate edge requires a priori Hamiltonian knowledge and that parameter variations and waveform distortion are unavoidable, with experimental calibration left out of scope; this is an honest practical limitation, not circularity. Both schemes are additionally benchmarked with stated T1 and 1/f-noise assumptions via Lindblad simulations (Appendix C), so the central claims are self-contained numerical predictions. No specific circular reduction can be exhibited, so the circularity score is 0.

Assumptions & free parameters 7 free parameters · 5 assumptions · 0 invented entities

The central claims rest on chosen circuit parameters (design choices) and on standard modeling assumptions for superconducting circuits. No new physical entities are introduced. The free parameters are numerous, which is typical for a quantum device proposal; the reported fidelities depend directly on these choices and on the validity of the noise models.

free parameters (7)

Adiabatic gate: fluxonium charging energies = EC,1 = EC,2 = 1.5 GHz
Design choice from Sec III; sets the qubit frequencies near 3 GHz and affects charge noise sensitivity and anharmonicity.
Adiabatic gate: fluxonium Josephson and inductive energies = EJ,1 = 4.1 GHz, EJ,2 = 3.8 GHz, EL,1 = 0.18 GHz, EL,2 = 0.14 GHz
Chosen to place qubit transitions and high-energy states; the |2> detuning relies on these values.
Adiabatic gate: coupler energies = EC,c = 180 MHz, EJ,c = 18 GHz
Coupler frequency is set above fluxoniums; changes the ZZ cancellation point and gate speed.
Adiabatic gate: coupling strengths = J_c,1 = J_c,2 = 600 MHz, J_12 = -100 MHz
Strong coupling needed for adiabaticity and gate speed; trade-off with stray couplings discussed in Sec III C.
Microwave gate: fluxonium and coupler parameters = EC,1(2) = 1.2 GHz, EJ,1(2) = 6.1(6) GHz, EL,1(2) = 0.17(0.15) GHz, EC,c = 300 MHz, EJ,c = 25 GHz
Different set chosen to put fluxonium |3> states near the coupler transition (Sec IV A).
Microwave gate: couplings = J_C,1(2) = 450 MHz, J_12 = 120 MHz
Sets the level repulsion and the splitting of the coupler first excited state.
Pulse shape parameters = Edge durations 10 or 32 ns; flat durations optimized per gate
Pulse edges and flat lengths are optimized to minimize leakage and phase error (Sec III B, Sec IV B).

assumptions (5)

domain assumption Lindblad master equation with Markovian dissipation
Used in Appendix C2 to model T1 decoherence for qubits and coupler; assumes environment correlation time is short.
domain assumption Quasistatic Gaussian approximation for 1/f flux noise
Sec III C replaces 1/f noise with a static random flux offset distributed with variance from S_phi(f) = A^2/f, ignoring time dependence and higher-frequency components.
domain assumption Single-mode description of fluxonium and transmon elements
The circuit Hamiltonian (Eq. 1) treats each element as one mode with a cosine potential; higher modes and sum modes are neglected (Appendix A).
standard math Adiabatic theorem holds along the flux pulse trajectory
The constant-leakage-rate edge design (Sec III B) relies on slow evolution relative to energy gaps, with residual leakage treated perturbatively.
domain assumption Integer fluxoniums are first-order insensitive to flux noise
The error budget neglects fluxonium flux noise at integer flux quanta, stated in Sec III C.

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Cite this review

Pith. "Pith review of Transmon-assisted high-fidelity controlled-Z gates for integer fluxonium qubits." pith.science (2026). https://pith.science/paper/T3E4FRTF

@misc{pith2026250904776,
  author       = {Pith},
  title        = {Pith review of: Transmon-assisted high-fidelity controlled-Z gates for integer fluxonium qubits},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/T3E4FRTF}},
  note         = {Machine review of arXiv:2509.04776}
}

abstract

Fluxoniums, as partially-protected superconducting qubits are promising to be employed to build high-performance large-scale quantum processor. The recently proposed ``integer fluxonium" operates at zero external flux bias, with a frequency of approximately 3 GHz. Single-qubit gate fidelity has been demonstrated to exceed $99.9\%$, while two-qubit gate schemes and scalable architectures remain underexplored. In this work, we investigate a fluxonium-transmon-fluxonium (FTF) coupling architecture using integer fluxoniums. We first confirm suppression of $ZZ$ interaction in the FTF system and then propose two high-fidelity controlled-$Z$ (CZ) gate schemes utilizing the coupler control: a flux-activated adiabatic gate scheme and a microwave-activated non-adiabatic gate scheme. Both schemes are capable of achieving low coherent error on the order of $1 \times 10^{-6}$ within gate durations of several tens of nanoseconds. Additionally, we discuss a hybrid circuit system in which an integer fluxonium is coupled to a conventional fluxonium through a transmon coupler. Our proposal provides insights for future implementations of large-scale quantum circuits based on integer fluxonium devices.

Figures

Figures reproduced from arXiv: 2509.04776 by the authors.

**Figure 2.** FIG. 2. Adiabatic controlled-phase gate simulation with [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗

**Figure 3.** FIG. 3. Optimization of the adiabatic gate pulses and gate [PITH_FULL_IMAGE:figures/full_fig_p005_3.png] view at source ↗

Figures from the paper (9 more)

**Figure 4.** Figure 4: FIG. 4. Microwave-activated CZ gate scheme simulations. [PITH_FULL_IMAGE:figures/full_fig_p007_4.png]

**Figure 5.** Figure 5: FIG. 5. Gate fidelities after ac-Stark phases cancellation. (a) [PITH_FULL_IMAGE:figures/full_fig_p008_5.png]

**Figure 6.** Figure 6: FIG. 6. Revised CZ gate schemes in the IF-T-F system. [PITH_FULL_IMAGE:figures/full_fig_p009_6.png]

**Figure 7.** Figure 7: FIG. 7. Circuit models of FTF circuits of one-dimensional scaling archtecture. The capacitance network is simplified for the [PITH_FULL_IMAGE:figures/full_fig_p011_7.png]

**Figure 8.** Figure 8: FIG. 8. Circuit model of FTF circuit of two-dimensional scaling with grounded transmons. [PITH_FULL_IMAGE:figures/full_fig_p013_8.png]

**Figure 9.** Figure 9: FIG. 9 [PITH_FULL_IMAGE:figures/full_fig_p015_9.png]

**Figure 10.** Figure 10: FIG. 10 [PITH_FULL_IMAGE:figures/full_fig_p016_10.png]

**Figure 11.** Figure 11: (a) and (b). When calculating the phase tunability for our Gaussian pulse, we first use the spin model, resulting a rate of 0.663πTg. Then we use the full Hamiltonian containing 50 energy levels, but only include the charge matrix element n01 by setting n12, n23 and…

**Figure 12.** Figure 12: FIG. 12 [PITH_FULL_IMAGE:figures/full_fig_p017_12.png]

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Pith tools

Reviewed August 15, 2026 · model on record in the stance chip above.

[1] [1]

The circuit diagram is shown in Fig

1D chain Starting from the node methods, we first consider a one-dimension fluxonium qubit chain with grounded transmons as couplers. The circuit diagram is shown in Fig. 7, and here we neglect the small and qualitatively unimportant capacitance in this analysis. The capaci- tance matrix of this circuit can be written as C=   Cf −Cf2 0 0 0 0 0 ...

work page

[2] [2]

A fluxo- nium qubit (data qubit) is capacitively coupled to four transmons (couplers), as shown in Fig

2D lattice Here we consider a square-lattice topology. A fluxo- nium qubit (data qubit) is capacitively coupled to four transmons (couplers), as shown in Fig. 8. Again, we neglect the small and qualitatively unimportant capac- itance in the analysis. Elements of ˜C−1 for this circuit are given by 13 TABLE II. Calculated Hamiltonian parameters of the one d...

work page

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I. V. Pechenezhskiy, R. A. Mencia, L. B. Nguyen, Y.- H. Lin, and V. E. Manucharyan, The superconducting quasicharge qubit, Nature585, 368 (2020)

2020

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The edge profile is solved based on functionsD ij(φext,c) which are obtained through interpolations of the numerically calculated dis- crete values

Optimization for coherent error As described in main text, the optimized pulse is com- posed of the constant-leakage-rate edge and the residual- leakage-suppressed flat duration. The edge profile is solved based on functionsD ij(φext,c) which are obtained through interpolations of the numerically calculated dis- crete values. Furthermore, although this op...

work page

[5] [5]

Calculated Hamiltonian parameters of the two dimension extension case corresponding to the set of capacitance of the same identifier in the table

Incoherent error simulation We model the environment-induced dissipation as Markovian process, and analyze the effect on gate fidelity by master equation ˙ρ=−i h[ ˆH,ρ] + X k [ˆLk ˆρˆL† k− 1 2(ˆL† k ˆLk ˆρ+ ˆρˆL† k ˆLk)],(C1) 15 TABLE III. Calculated Hamiltonian parameters of the two dimension extension case corresponding to the set of capacitance of the ...

work page

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R. A. Mencia, W.-J. Lin, H. Cho, M. G. Vavilov, and V. E. Manucharyan, Integer fluxonium qubit, PRX Quantum5, 040318 (2024)

work page 2024

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Gyenis, P

A. Gyenis, P. S. Mundada, A. Di Paolo, T. M. Hazard, X. You, D. I. Schuster, J. Koch, A. Blais, and A. A. Houck, Experimental realization of a protected supercon- ducting circuit derived from the 0–πqubit, PRX Quan- tum2, 010339 (2021)

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E. L. Rosenfeld, C. T. Hann, D. I. Schuster, M. H. Ma- theny, and A. A. Clerk, High-fidelity two-qubit gates be- tween fluxonium qubits with a resonator coupler, PRX Quantum5, 040317 (2024)

2024