Quasiparticle-induced decoherence of a driven superconducting qubit

Mykola KishmarPavel KurilovichVlad KurilovichThomas ConnollyAndrey KlotsIgor Aleiner

article2025Physical Review Applied9 citations

Establishes a microscopic theory of quasiparticle-induced decoherence in driven superconducting qubits, identifying how photon-assisted tunneling and drive-induced pair creation impose fundamental fidelity limits on microwave gates and readout operations.

Listen

Superconducting quantum processors require near-flawless operation to achieve practical computing power, yet they frequently suffer performance degradation from broken superconducting electron pairs, known as quasiparticles. To protect qubits from these disruptions, designers developed "gap engineering," a technique that creates an energy barrier across the qubit's junction to block quiescent quasiparticles from moving. However, actual computing operations require applying microwave control signals to perform gates and readout, raising urgent questions about whether these applied fields inadvertently bypass built-in hardware defenses.

The article develops an analytical theory to evaluate how microwave control fields reactivate quasiparticle-induced errors in superconducting qubits. Specifically, it models two distinct failure channels in flux-tunable transmon qubits: drive-assisted tunneling of existing quasiparticles and the generation of new quasiparticles through multi-photon pair breaking.

To conduct this evaluation, the researchers used a diagrammatic perturbation theory framework combined with standard quantum transition rate modeling. The model accounts for the non-linear interaction between the microwave drive, the qubit state dynamics, and the electron tunneling channels, enabling the estimation of error rates across single- and multi-photon processes under realistic device parameters.

The analysis reveals three critical findings. First, microwave control signals provide the extra energy required for existing quasiparticles to overcome the engineered gap barrier, re-enabling unwanted relaxation above specific drive frequency thresholds. Second, multi-photon absorption processes bypass gap engineering barriers at even lower drive frequencies and match or exceed single-photon error rates under typical operating configurations. Third, sufficiently strong or high-frequency control tones directly break intact Cooper pairs, generating new quasiparticles and triggering qubit state leakage; for example, high-frequency readout at sixty gigahertz in an aluminum-based qubit degrades operational fidelity by an estimated five percent or more.

These findings demonstrate that gap engineering alone is insufficient to protect quantum processors during active execution. Whenever control fields are applied, quasiparticles set a fundamental fidelity ceiling on quantum logic gates and measurement operations, especially following ionizing radiation bursts when quasiparticle densities spike. The results indicate that hardware designers cannot indefinitely increase readout frequencies or control power without introducing severe error penalties.

To mitigate these error mechanisms, engineering teams should optimize hardware by increasing the superconducting gap differentials across junctions to raise multi-photon threshold frequencies. Device developers should also integrate physical quasiparticle traps to clear stray excitations away from junctions before operations begin. Furthermore, quantum control teams must co-design pulse shapes and frequency allocations to avoid multi-photon pair-breaking regimes.

The findings rely on theoretical modeling of transmon qubits within low-temperature approximations and tree-level diagrammatic expansions. While the analytical rates align with independent numerical simulations, experimental testing on physical hardware across varied radiation environments is necessary to confirm the exact quantitative bounds.

Columbia University Google Yale University microwaves quantum gates Quasiparticle-induced decoherence Microwave-assisted quasiparticle tunneling Flux-tunable transmon

arXiv: 2505.00769

No sufficiently relevant recommendations were found.

Cover for Quasiparticle-induced decoherence of a driven superconducting qubit

Abstract

We develop a theory for two quasiparticle-induced decoherence mechanisms of a driven superconducting qubit. In the first mechanism, an existing quasiparticle (QP) tunnels across the qubit's Josephson junction while simultaneously absorbing a qubit excitation and one (or several) photons from the drive. In the second mechanism, a qubit transition occurs during the non-linear absorption process converting multiple drive quanta into a pair of new QPs. Both mechanisms can remain significant in gap engineered qubits whose coherence is insensitive to QPs without the drive. Our theory establishes a fundamental limitation on fidelity of the microwave qubit operations, such as readout and gates, stemming from QPs.

Topics

microwaves quantum gates

Keywords

Quasiparticle-induced decoherence Microwave-assisted quasiparticle tunneling Flux-tunable transmon Nonequilibrium quasiparticles Multi-excitation resonances Cooper-pair breaking Single-photon process Strong drive

References
Supplemental Materials for “Quasiparticle-induced decoherence of a driven superconducting qubit”
I GENERAL PERTURBATION THEORY FOR THE QP TUNNELING AMPLITUDES
II Generalization of Eq. (10) to arbitrary flux Φ\Phi
III Comparison of one- and two-photon qubit relaxation processes at Φ=0\Phi=0
IV Two-photon process of qubit excitation
V Generalization of Eq. (13) to arbitrary initial and final qubit states
References

Knowls

Knowl 1 — Single-Photon Microwave-Assisted Quasiparticle Relaxation Rate in Flux-Tunable Transmons
theoretical result
In a gap-engineered transmon qubit with gap difference $\delta\Delta = \Delta_R - \Delta_L > 0$ across the Josephson junction (JJ), energy relaxation of the first excited state ( $|1\rangle \to |0\rangle$ ) can be reanimated by a microwave drive of frequency $\omega_d$ and dimensionless phase amplitude $a$ when the drive photon assists an existing quasiparticle (QP) in overcoming the gap barrier. The single-photon QP-induced relaxation rate as a function of external magnetic flux bias $\Phi$ is given by

$\Gamma_{1\to 0}^{(1)} = \frac{|\omega_{\text{ac}}| x_{\text{QP}}}{4\pi} \left\{ S_+[\omega_d + \omega_q(\Phi)] \left( \frac{\omega_q^2(0)}{\omega_q^2(\Phi)} - 1 \right) + S_-[\omega_d + \omega_q(\Phi)] \left( \frac{\omega_q^2(0)}{\omega_q^2(\Phi)} + 1 \right) \right\},$

where $\omega_q(\Phi)$ is the flux-dependent transmon qubit frequency in the absence of the drive, $\omega_q(0)$ is the maximum qubit frequency at zero flux $\Phi = 0$ , $x_{\text{QP}} = n_{\text{QP}}/(2\nu_0 \bar{\Delta})$ is the normalized QP density ( $n_{\text{QP}}$ is the QP density, $\nu_0$ is the normal-state density of states, and $\bar{\Delta} = (\Delta_L + \Delta_R)/2$ ), and $\omega_{\text{ac}} = -\frac{1}{8}\omega_q(\Phi) a^2 \omega_d^4 / [\omega_d^2 - \omega_q^2(\Phi)]^2$ is the qubit ac-Stark shift.

For "cold" quasiparticles localized within an energy window $\delta E \ll \delta\Delta$ near the gap edge of the low-gap lead, the structure factors $S_\pm[\omega]$ for $\omega \equiv \omega_d + \omega_q(\Phi)$ exhibit an absorption threshold $\hbar\omega > \delta\Delta$ :

$S_\pm[\omega] = \frac{1}{2} \left( \frac{2\bar{\Delta}}{\hbar\omega - \delta\Delta} \right)^{\pm 1/2} \Theta(\hbar\omega - \delta\Delta),$

where $\Theta(x)$ is the Heaviside step function. The single-photon process becomes kinematically allowed when $\omega_d > \delta\Delta/\hbar - \omega_q(\Phi)$ .
Knowl 2 — Multi-Photon Cooper-Pair Breaking Transition Rates in Driven Superconducting Qubits
theoretical result
A microwave drive of frequency $\omega_d$ can induce transitions between transmon qubit states $|i\rangle$ and $|f\rangle$ by breaking a Cooper pair at the Josephson junction through the absorption of $n$ drive photons. The energy required to break a pair and change the qubit state is at least $2\bar{\Delta} + \hbar\omega_{fi}$ , where $\bar{\Delta} = (\Delta_L + \Delta_R)/2$ and $\hbar\omega_{fi} = E_f - E_i$ . The minimum number of drive photons is $n = \lceil (2\bar{\Delta} + \hbar\omega_{fi}) / (\hbar\omega_d) \rceil$ .

To leading order in the drive amplitude $a$ , the generalized transition rate across the SQUID junctions $j \in \{1, 2\}$ is

$\tilde{\Gamma}_{i\to f}^{(n)} = \frac{8}{\pi} \sum_{j=1,2} \frac{E_{Jj}}{\hbar} \left( \frac{a^n}{4^n n!} \right)^2 \left\{ \tilde{S}_{p(n)}[\omega_{if} + n\omega_d] |\langle f| \cos(\hat{\phi}_j/2) |i\rangle |^2 + \tilde{S}_{-p(n)}[\omega_{if} + n\omega_d] |\langle f| \sin(\hat{\phi}_j/2) |i\rangle |^2 \right\},$

where $\omega_{if} = (E_i - E_f)/\hbar$ , $E_{Jj}$ are the Josephson energies of the two junctions, $\hat{\phi}_j = \hat{\phi} - (-1)^j \pi\Phi/\Phi_0$ , and the parity index is $p(n) = +$ for even $n$ and $p(n) = -$ for odd $n$ .

For the specific transmon relaxation process $|1\rangle \to |0\rangle$ , the rate expressed in terms of the ac-Stark shift $\omega_{\text{ac}}$ is

$\tilde{\Gamma}_{1\to 0}^{(n)} = \frac{\omega_q(\Phi)}{\pi 2^{n+1} (n!)^2} \left( \frac{|\omega_{\text{ac}}|}{\omega_q(\Phi)} \right)^n \left\{ \tilde{S}_{p(n)}[\omega_q(\Phi) + n\omega_d] \left( \frac{\omega_q^2(0)}{\omega_q^2(\Phi)} - 1 \right) + \tilde{S}_{-p(n)}[\omega_q(\Phi) + n\omega_d] \left( \frac{\omega_q^2(0)}{\omega_q^2(\Phi)} + 1 \right) \right\}.$

The pair-breaking structure factors $\tilde{S}_\pm[\omega]$ are nonzero only above threshold $\omega > 2\bar{\Delta}/\hbar$ :

$\tilde{S}_\pm[\omega] = \int_{\Delta_L}^{\hbar\omega - \Delta_R} \frac{d\varepsilon}{\bar{\Delta}} \frac{\varepsilon(\hbar\omega - \varepsilon) \pm \Delta_L \Delta_R}{\sqrt{\varepsilon^2 - \Delta_L^2}\sqrt{(\hbar\omega - \varepsilon)^2 - \Delta_R^2}}.$

Near the threshold $\delta\omega \equiv \omega - 2\bar{\Delta}/\hbar \ll \bar{\Delta}/\hbar$ , their asymptotic forms are $\tilde{S}_+[\omega] \approx \pi + \frac{\pi}{4}\frac{\hbar\delta\omega}{\bar{\Delta}}$ and $\tilde{S}_-[\omega] \approx \frac{\pi}{2}\sqrt{\frac{\hbar\delta\omega}{\bar{\Delta}}}$ . The transition rate for excitation ( $|0\rangle \to |1\rangle$ ) is obtained by replacing $\omega_q(\Phi) \to -\omega_q(\Phi)$ in the argument of $\tilde{S}_{\pm p(n)}$ .
Knowl 3 — Two-Photon-Assisted Quasiparticle Relaxation Rate and Interference Cancellation at Zero Flux
theoretical result
In single-photon QP-assisted relaxation, the transition amplitude at zero flux bias ( $\Phi = 0$ ) is proportional to $u_k u_{k'} - v_k v_{k'}$ , which vanishes for low-energy quasiparticles ( $u \approx v \approx 1/\sqrt{2}$ ) due to destructive interference between particle ( $uu$ ) and hole ( $vv$ ) tunneling channels. This suppresses $\Gamma_{1\to 0}^{(1)}$ at $\Phi = 0$ as it depends only on the small structure factor $S_- \ll S_+$ .

In contrast, for a two-photon absorption process, the particle and hole tunneling amplitudes interfere constructively ( $u_k u_{k'} + v_k v_{k'}$ ), coupling the rate to the dominant structure factor $S_+$ . At arbitrary flux bias $\Phi$ , the two-photon relaxation rate is

$\Gamma_{1\to 0}^{(2)} = \frac{1}{32\pi} \frac{\omega_{\text{ac}}^2 x_{\text{QP}}}{\omega_q(\Phi)} \{1 + 4 D_0[2\omega_d + \omega_q(\Phi)]\}^2 \left\{ S_+[2\omega_d + \omega_q(\Phi)] \left( \frac{\omega_q^2(0)}{\omega_q^2(\Phi)} + 1 \right) + S_-[2\omega_d + \omega_q(\Phi)] \left( \frac{\omega_q^2(0)}{\omega_q^2(\Phi)} - 1 \right) \right\},$

where $D_0(\omega) = \omega_q^2(\Phi)/[\omega^2 - \omega_q^2(\Phi)]$ is the dimensionless transmon response function describing screening by parametric frequency oscillations at $2\omega_d$ .

At $\Phi = 0$ , this reduces to

$\Gamma_{1\to 0}^{(2)}(\Phi = 0) = \frac{1}{16\pi} \frac{\omega_{\text{ac}}^2 x_{\text{QP}}}{\omega_q(0)} \{1 + 4 D_0[2\omega_d + \omega_q(0)]\}^2 S_+[2\omega_d + \omega_q(0)].$

Because $S_+ \gg S_-$ , the two-photon relaxation rate can be comparable to the one-photon rate at $\Phi = 0$ for typical readout drive strengths ( $\Gamma_{1\to 0}^{(2)} / \Gamma_{1\to 0}^{(1)} \sim 0.1 - 0.4$ ), and it operates over a wider frequency band with threshold $\omega_d > [\delta\Delta/\hbar - \omega_q(\Phi)]/2$ .
Knowl 4 — Microwave-Assisted Quasiparticle-Induced Qubit Excitation Rates and Resonant Enhancement
theoretical result
A microwave drive can also cause quasiparticle-assisted qubit excitation transitions ( $|0\rangle \to |1\rangle$ and $|1\rangle \to |2\rangle$ ). The single-photon-assisted excitation rate is

$\Gamma_{0\to 1}^{(1)} = \frac{|\omega_{\text{ac}}| x_{\text{QP}}}{4\pi} \left\{ S_+[\omega_d - \omega_q(\Phi)] \left( \frac{\omega_q^2(0)}{\omega_q^2(\Phi)} - 1 \right) + S_-[\omega_d - \omega_q(\Phi)] \left( \frac{\omega_q^2(0)}{\omega_q^2(\Phi)} + 1 \right) \right\},$

which has a threshold $\omega_d > \delta\Delta/\hbar + \omega_q(\Phi)$ . The rate of leakage to the non-computational state $|2\rangle$ satisfies $\Gamma_{1\to 2}^{(1)} \approx 2\Gamma_{0\to 1}^{(1)}$ .

The two-photon-assisted excitation rate is

$\Gamma_{0\to 1}^{(2)} = \frac{1}{32\pi} \frac{\omega_{\text{ac}}^2 x_{\text{QP}}}{\omega_q(\Phi)} \{1 + 4 D_0[2\omega_d - \omega_q(\Phi)]\}^2 \left\{ S_+[2\omega_d - \omega_q(\Phi)] \left( \frac{\omega_q^2(0)}{\omega_q^2(\Phi)} + 1 \right) + S_-[2\omega_d - \omega_q(\Phi)] \left( \frac{\omega_q^2(0)}{\omega_q^2(\Phi)} - 1 \right) \right\},$

with threshold $\omega_d > [\delta\Delta/\hbar + \omega_q(\Phi)]/2$ . Because the response function contains a pole at $2\omega_d \approx \omega_{02} \approx 2\omega_q(\Phi)$ due to a virtual $|0\rangle \to |2\rangle$ intermediate excitation, the excitation rate is resonantly enhanced over the two-photon relaxation rate near this condition:

$\frac{\Gamma_{0\to 1}^{(2)}}{\Gamma_{1\to 0}^{(2)}} \sim \left( \frac{\omega_d}{\omega_d - \omega_{02}/2} \right)^2 \gg 1.$
Knowl 5 — Bounds on Superconducting Qubit Readout and Gate Fidelity Imposed by Quasiparticles
theoretical result
Microwave-assisted quasiparticle tunneling imposes lower bounds on error rates for dispersive readout and single-qubit microwave gates.

For a dispersive readout pulse of duration $t_{\text{RO}}$ , the readout error due to QP tunneling relaxation during the pulse is bounded by

$1 - F \gtrsim \Gamma_{1\to 0}^{(1)} t_{\text{RO}} = \alpha \cdot |\omega_{\text{ac}}| t_{\text{RO}} \cdot x_{\text{QP}},$

where $\alpha$ is a dimensionless parameter of order unity ( $\,\alpha \sim 1\,$ for generic $\Phi \neq 0$ ) determined by $\omega_q(\Phi)$ , $\omega_d$ , and the gap values $\Delta_L, \Delta_R$ . Because high-fidelity readout requires a signal-to-noise ratio product $|\omega_{\text{ac}}| t_{\text{RO}} \sim 100$ , the readout infidelity is fundamentally lower-bounded by $1 - F \gtrsim 100 \cdot x_{\text{QP}}$ . For QP densities elevated by ionizing radiation ( $x_{\text{QP}} \gtrsim 10^{-4}$ ), this sets an infidelity floor $1 - F \gtrsim 0.01$ .

For a single-qubit resonant drive gate of duration $t_{\text{gate}}$ , regularizing the single-photon rate divergence by the transmon charging energy $E_C/\hbar$ yields the gate infidelity bound

$1 - F \gtrsim \beta \cdot \frac{x_{\text{QP}}}{E_C t_{\text{gate}} / \hbar},$

where $\beta \sim 1$ . For optimal pulse shapes where $E_C t_{\text{gate}} / \hbar \sim 1$ , the gate infidelity is bounded by $1 - F \gtrsim x_{\text{QP}}$ .
Knowl 6 — Performance Limit on High-Frequency Dispersive Readout from Multi-Photon Pair Breaking
limitation
While dispersive readout fidelity can be improved by increasing the measurement tone frequency to the regime $\omega_d \gg \omega_q$ , the frequency cannot be increased arbitrarily because multi-photon Cooper-pair breaking transitions ( $\,n\hbar\omega_d + \hbar\omega_q \ge 2\bar{\Delta}\,$ ) activate and degrade fidelity.

For example, in a $5\text{ GHz}$ aluminum qubit with superconducting gap $\Delta/h \approx 50\text{ GHz}$ read out with a high-frequency tone at $\omega_d/2\pi = 60\text{ GHz}$ , the absorption of $n = 2$ drive photons breaks a Cooper pair at the Josephson junction ( $2\hbar\omega_d + \hbar\omega_q \approx 125\text{ GHz} > 2\Delta$ ). Evaluating the $n=2$ pair-breaking transition rate yields a fundamental limit on the readout error of $1 - F \gtrsim 0.05$ .
Knowl 7 — Hamiltonian Model for a Driven Transmon with Quasiparticles and Microwave-Assisted Tunneling
model/method
The dynamics of a driven flux-tunable transmon in the presence of quasiparticles is described by the full Hamiltonian $\hat{H} = \hat{H}_\phi(t) + \hat{H}_{\text{qp}} + \hat{H}_T(t) + \hat{H}_{\text{CP}}(t)$ :
1. Quantized phase dynamics across two SQUID junctions $j \in \{1, 2\}$ : $\hat{H}_\phi(t) = 4E_C \hat{N}^2 - \sum_{j=1,2} E_{Jj} \cos[\hat{\phi}_j - \phi_d(t)],$ where $\hat{\phi}_j = \hat{\phi} - (-1)^j \pi\Phi/\Phi_0$ , $\hat{N} = -i d/d\hat{\phi}$ , $E_C$ is the charging energy, $E_{Jj}$ are the junction Josephson energies, and $\phi_d(t) = a \cos(\omega_d t)$ is the microwave drive.
2. Free quasiparticle Hamiltonian in leads $\alpha \in \{L, R\}$ : $\hat{H}_{\text{qp}} = \sum_{k\sigma\alpha} \varepsilon_{k\alpha} \hat{\gamma}_{k\sigma\alpha}^\dagger \hat{\gamma}_{k\sigma\alpha},$ where $\varepsilon_{k\alpha} = \sqrt{\Delta_\alpha^2 + \xi_{k\alpha}^2}$ and $\hat{\gamma}_{k\sigma\alpha}$ are Bogoliubov quasiparticle annihilation operators for state $k$ and spin $\sigma = \pm$ .
3. Quasiparticle tunneling under microwave drive: $\hat{H}_T(t) = \sum_{kk'\sigma j} t_{j,kk'} \left( e^{\frac{i}{2}[\phi_d(t) - \hat{\phi}_j]} u_{kR} u_{k'L} - e^{-\frac{i}{2}[\phi_d(t) - \hat{\phi}_j]} v_{kR} v_{k'L} \right) \hat{\gamma}_{k\sigma R}^\dagger \hat{\gamma}_{k'\sigma L} + \text{h.c.},$ where $u_{k\alpha} = \sqrt{(1 + \xi_{k\alpha}/\varepsilon_{k\alpha})/2}$ and $v_{k\alpha} = \sqrt{(1 - \xi_{k\alpha}/\varepsilon_{k\alpha})/2}$ are BCS coherence factors, and $t_{j,kk'}$ is the tunneling matrix element relating to junction normal-state conductance $G_{Tj} = 4\pi^2 \nu_0^2 |t_j|^2$ .
4. Cooper-pair breaking under microwave drive: $\hat{H}_{\text{CP}}(t) = \sum_{kk'\sigma j} \bar{\sigma} t_{j,kk'} \left( e^{\frac{i}{2}[\phi_d(t) - \hat{\phi}_j]} u_{k'R} v_{kL} + e^{-\frac{i}{2}[\phi_d(t) - \hat{\phi}_j]} v_{k'R} u_{kL} \right) \hat{\gamma}_{k'\bar{\sigma} R}^\dagger \hat{\gamma}_{k\sigma L}^\dagger + \text{h.c.} + \sum_{j=1,2} E_{Jj} \cos[\hat{\phi}_j - \phi_d(t)],$ with $\bar{\sigma} = -\sigma$ .
Knowl 8 — Diagrammatic Perturbation Theory for Multi-Photon Quasiparticle-Qubit Interactions
model/method
To evaluate transition amplitudes involving arbitrary numbers of drive photons $n$ and qubit phase fluctuations $\hat{\phi}^m$ , the unperturbed Hamiltonian is chosen as the harmonic qubit oscillator plus free quasiparticles:

$\hat{H}_0 = 4E_C \hat{N}^2 + \frac{J_0(a) E_J(\Phi) \hat{\phi}^2}{2} + \sum_{k\sigma\alpha} \varepsilon_{k\alpha} \hat{\gamma}_{k\sigma\alpha}^\dagger \hat{\gamma}_{k\sigma\alpha},$

where $E_J(\Phi) = \sqrt{E_{J1}^2 + E_{J2}^2 + 2E_{J1}E_{J2}\cos(\pi\Phi/\Phi_0)}$ and $J_0(a)$ renormalizes the Josephson potential. The interaction Hamiltonian is expanded in drive Fourier harmonics $e^{-i n \omega_d t}$ and phase powers $\hat{\phi}^m$ :

$\hat{H}_{\text{int}} = \sum_{m>2} \hat{H}_\phi^{(m,0)} + \sum_{n\neq 0, m\ge 1} e^{-i n \omega_d t} \hat{H}_\phi^{(m,n)} + \sum_{j,n,m} e^{-i n \omega_d t} \hat{H}_{Tj}^{(m,n)},$

with vertices connected by the retarded transmon phase propagator

$D(\omega) = \phi_{\text{ZPF}}^2 \frac{2\omega_q(\Phi)}{\omega^2 - \omega_q^2(\Phi)},$

where $\phi_{\text{ZPF}} = (2E_C/E_J)^{1/4}$ . The screening of the drive by transmon plasma oscillations replaces every drive line $a$ with the effective screened amplitude

$\tilde{a} = a [1 + E_J D(\omega_d)] = a \frac{\omega_d^2}{\omega_d^2 - \omega_q^2(\Phi)}.$

Coverage note — None was omitted; all primary theoretical models, single- and multi-photon transition rate expressions for QP tunneling and pair-breaking, diagrammatic rules, and fidelity bounds were included.

References

1.L. I. Glazman and G. Catelani, SciPost Phys. Lect. Notes, 31 (2021).
2.J. Aumentado, M. W. Keller, J. M. Martinis, and M. H. Devoret, Phys. Rev. Lett. 92, 066802 (2004).
3.M. D. Shaw, R. M. Lutchyn, P. Delsing, and P. M. Echternach, Phys. Rev. B 78, 024503 (2008).
4.M. Lenander, H. Wang, R. C. Bialczak, E. Lucero, M. Mariantoni, M. Neeley, A. D. O’Connell, D. Sank, M. Weides, J. Wenner, T. Yamamoto, Y. Yin, J. Zhao, A. N. Cleland, and J. M. Martinis, Phys. Rev. B 84, 024501 (2011).
5.D. Ristè, C. C. Bultink, M. J. Tiggelman, R. N. Schouten, K. W. Lehnert, and L. DiCarlo, Nat. Commun. 4, 1913 (2013).
6.I. M. Pop, K. Geerlings, G. Catelani, R. J. Schoelkopf, L. I. Glazman, and M. H. Devoret, Nature 508, 369 (2014).
7.U. Vool, I. M. Pop, K. Sliwa, B. Abdo, C. Wang, T. Brecht, Y. Y. Gao, S. Shankar, M. Hatridge, G. Catelani, M. Mirrahimi, L. Frunzio, R. J. Schoelkopf, L. I. Glazman, and M. H. Devoret, Phys. Rev. Lett. 113, 247001 (2014).
8.C. Wang, Y. Y. Gao, I. M. Pop, U. Vool, C. Axline, T. Brecht, R. W. Heeres, L. Frunzio, M. H. Devoret, G. Catelani, L. I. Glazman, and R. J. Schoelkopf, Nat. Commun. 5, 5836 (2014).
9.A. Bespalov, M. Houzet, J. S. Meyer, and Y. V. Nazarov, Phys. Rev. Lett. 117, 117002 (2016).
10.K. Serniak, M. Hays, G. de Lange, S. Diamond, S. Shankar, L. D. Burkhart, L. Frunzio, M. Houzet, and M. H. Devoret, Phys. Rev. Lett. 121, 157701 (2018).
11.K. Serniak, S. Diamond, M. Hays, V. Fatemi, S. Shankar, L. Frunzio, R. Schoelkopf, and M. Devoret, Phys. Rev. Appl. 12, 014052 (2019).
12.S. Diamond, V. Fatemi, M. Hays, H. Nho, P. D. Kurilovich, T. Connolly, V. R. Joshi, K. Serniak, L. Frunzio, L. I. Glazman, and M. H. Devoret, PRX Quantum 3, 040304 (2022).
13.T. Connolly, P. D. Kurilovich, S. Diamond, H. Nho, C. G. L. Bøttcher, L. I. Glazman, V. Fatemi, and M. H. Devoret, Physical Review Letters 132 (2024), 10.1103/PhysRevLett.132.217001.
14.A. P. Vepsäläinen, A. H. Karamlou, J. L. Orrell, A. S. Dogra, B. Loer, F. Vasconcelos, D. K. Kim, A. J. Melville, B. M. Niedzielski, J. L. Yoder, S. Gustavsson, J. A. Formaggio, B. A. VanDevender, and W. D. Oliver, Nature 584, 551 (2020).
15.C. D. Wilen, S. Abdullah, N. A. Kurinsky, C. Stanford, L. Cardani, G. D’Imperio, C. Tomei, L. Faoro, L. B. Ioffe, C. H. Liu, A. Opremcak, B. G. Christensen, J. L. DuBois, and R. McDermott, Nature 594, 369 (2021).
16.L. Cardani, F. Valenti, N. Casali, G. Catelani, T. Charpentier, M. Clemenza, I. Colantoni, A. Cruciani, G. D’Imperio, L. Gironi, L. Grünhaupt, D. Gusenkova, F. Henriques, M. Lagoin, M. Martinez, G. Pettinari, C. Rusconi, O. Sander, C. Tomei, A. V. Ustinov, M. Weber, W. Wernsdorfer, M. Vignati, S. Pirro, and I. M. Pop, Nat. Commun. 12, 2733 (2021).
17.J. M. Martinis, Npj Quantum Inf. 7, 1 (2021).
18.M. McEwen, L. Faoro, K. Arya, A. Dunsworth, T. Huang, S. Kim, B. Burkett, A. Fowler, F. Arute, J. C. Bardin, et al., Nature Physics 18, 107 (2022).
19.E. Yelton, C. P. Larson, V. Iaia, K. Dodge, G. La Magna, P. G. Baity, I. V. Pechenezhskiy, R. McDermott, N. A. Kurinsky, G. Catelani, and B. L. T. Plourde, Phys. Rev. B 110, 024519 (2024).
20.R. Lutchyn, L. Glazman, and A. Larkin, Phys. Rev. B 72, 014517 (2005).
21.R. M. Lutchyn, L. I. Glazman, and A. I. Larkin, Phys. Rev. B 74, 064515 (2006).
22.J. M. Martinis, M. Ansmann, and J. Aumentado, Phys. Rev. Lett. 103, 097002 (2009).
23.G. Catelani, J. Koch, L. Frunzio, R. J. Schoelkopf, M. H. Devoret, and L. I. Glazman, Phys. Rev. Lett. 106, 077002 (2011).
24.G. Catelani, R. J. Schoelkopf, M. H. Devoret, and L. I. Glazman, Phys. Rev. B 84, 064517 (2011).
25.G. Catelani, S. E. Nigg, S. M. Girvin, R. J. Schoelkopf, and L. I. Glazman, Phys. Rev. B 86, 184514 (2012).
26.P. Kamenov, T. DiNapoli, M. Gershenson, and S. Chakram, “Suppression of quasiparticle poisoning in transmon qubits by gap engineering,” (2024), arXiv:2309.02655 [quant-ph].
27.M. McEwen, K. C. Miao, J. Atalaya, A. Bilmes, A. Crook, J. Bovaird, J. M. Kreikebaum, N. Zobrist, E. Jeffrey, B. Ying, A. Bengtsson, H.-S. Chang, A. Dunsworth, J. Kelly, Y. Zhang, E. Forati, R. Acharya, J. Iveland, W. Liu, S. Kim, B. Burkett, A. Megrant, Y. Chen, C. Neill, D. Sank, M. Devoret, and A. Opremcak, Phys. Rev. Lett. 133, 240601 (2024).
28.G. Marchegiani, L. Amico, and G. Catelani, PRX Quantum 3, 040338 (2022).
29.J. Koch, T. M. Yu, J. Gambetta, A. A. Houck, D. I. Schuster, J. Majer, A. Blais, M. H. Devoret, S. M. Girvin, and R. J. Schoelkopf, Phys. Rev. A 76, 042319 (2007).
30.P. Krantz, M. Kjaergaard, F. Yan, T. P. Orlando, S. Gustavsson, and W. D. Oliver, Appl. Phys. Rev. 6, 021318 (2019).
31.A. Blais, A. L. Grimsmo, S. M. Girvin, and A. Wallraff, Rev. Mod. Phys. 93 (2021), 10.1103/RevModPhys.93.025005.
32.A similar model was recently considered in Ref. 49 in the context of QP effects in superconducting cat qubits.
33.We make a conventional approximation, and drop the dependence of tj,kk′ on k and k′.
34.V. Ambegaokar and A. Baratoff, Phys. Rev. Lett. 10, 486 (1963).
35.“See supplmental materials for details,”.
36.M. Houzet, K. Serniak, G. Catelani, M. H. Devoret, and L. I. Glazman, Phys. Rev. Lett. 123, 107704 (2019).
37.L. V. Keldysh, (1964), 10.1142/9789811279461_0008.
38.We assume Γ(1)1→0 ≫ Γ(2)1→0. This is justified for a generic Φ ̸= 0, provided both processes are above the respective thresholds.
39.A. A. Clerk, M. H. Devoret, S. M. Girvin, F. Marquardt, and R. J. Schoelkopf, Rev. Mod. Phys. 82, 1155 (2010).
40.F. Swiadek, R. Shillito, P. Magnard, A. Remm, C. Hellings, N. Lacroix, Q. Ficheux, D. C. Zanuz, G. J. Norris, A. Blais, S. Krinner, and A. Wallraff, PRX Quantum 5, 040326 (2024).
41.P. D. Kurilovich, T. Connolly, C. G. L. Bøttcher, D. K. Weiss, S. Hazra, V. R. Joshi, A. Z. Ding, H. Nho, S. Diamond, V. D. Kurilovich, W. Dai, V. Fatemi, L. Frunzio, L. I. Glazman, and M. H. Devoret, “High-frequency readout free from transmon multi-excitation resonances,” (2025), arXiv:2501.09161 [quant-ph].
42.J. M. Chow, L. DiCarlo, J. M. Gambetta, F. Motzoi, L. Frunzio, S. M. Girvin, and R. J. Schoelkopf, Phys. Rev. A 82, 040305 (2010).
43.R.-P. Riwar and G. Catelani, Phys. Rev. B 100, 144514 (2019).
44.V. E. Manucharyan, J. Koch, L. I. Glazman, and M. H. Devoret, Science 326, 113 (2009), https://www.science.org/doi/pdf/10.1126/science.1175552.
45.Z. Leghtas, S. Touzard, I. M. Pop, A. Kou, B. Vlastakis, A. Petrenko, K. M. Sliwa, A. Narla, S. Shankar, M. J. Hatridge, M. Reagor, L. Frunzio, R. J. Schoelkopf, M. Mirrahimi, and M. H. Devoret, Science 347, 853–857 (2015).
46.A. Grimm, N. E. Frattini, S. Puri, S. O. Mundhada, S. Touzard, M. Mirrahimi, S. M. Girvin, S. Shankar, and M. H. Devoret, Nature 584, 205 (2020).
47.K. Lewellen, R. Mukherjee, H. Guo, S. Roy, V. Fatemi, and D. Chowdhury, “Frozonium: Freezing anharmonicity in floquet superconducting circuits,” (2025), arXiv:2501.10503 [cond-mat.mes-hall].
48.S. Chowdhury, M. Hays, S. R. Jha, K. Serniak, T. P. Orlando, J. A. Grover, and W. D. Oliver, “Theory of quasiparticle generation by microwave drives in superconducting qubits,” (2025), arXiv:2505.00773 [quant-ph].
49.K. S. Dubovitskii, D. M. Basko, J. S. Meyer, and M. Houzet, Phys. Rev. B 110, 024505 (2024).
50.Koch, J. et al. Charge-insensitive qubit design derived from the cooper pair box. Phys. Rev. A 76, 042319 (2007). URL https://link.aps.org/doi/10.1103/PhysRevA.76.042319.
51.Ziman, J. Elements of Advanced Quantum Theory (Cambridge University Press, 1969).
52.Swiadek, F. et al. Enhancing dispersive readout of superconducting qubits through dynamic control of the dispersive shift: Experiment and theory. PRX Quantum 5, 040326 (2024). URL https://link.aps.org/doi/10.1103/PRXQuantum.5.040326.
53.Kurilovich, P. D. et al. High-frequency readout free from transmon multi-excitation resonances (2025). URL https://arxiv.org/abs/2501.09161. 2501.09161.

Citation

MLA

Kishmar, M., et al. “Quasiparticle-induced Decoherence of a Driven Superconducting Qubit”. Physical Review Applied, vol. 26, no. 1, 2026, https://doi.org/10.1103/3q5z-tk7c.

APA

Kishmar, M., Kurilovich, P. D., Klots, A., Connolly, T., Aleiner, I. L., & Kurilovich, V. D. (2026). Quasiparticle-induced decoherence of a driven superconducting qubit. Physical Review Applied, 26(1). https://doi.org/10.1103/3q5z-tk7c

Chicago

Kishmar, M., P. D. Kurilovich, A. Klots, T. Connolly, I. L. Aleiner, and V. D. Kurilovich. 2026. “Quasiparticle-induced Decoherence of a Driven Superconducting Qubit”. Physical Review Applied 26 (1). https://doi.org/10.1103/3q5z-tk7c.

Harvard

Kishmar, M. et al. (2026) “Quasiparticle-induced decoherence of a driven superconducting qubit”, Physical Review Applied, 26(1). Available at: https://doi.org/10.1103/3q5z-tk7c.

Vancouver

1. Kishmar M, Kurilovich PD, Klots A, Connolly T, Aleiner IL, Kurilovich VD (2026) Quasiparticle-induced decoherence of a driven superconducting qubit. Physical Review Applied. https://doi.org/10.1103/3q5z-tk7c

BibTeX

@article{Kishmar_2026, title={Quasiparticle-induced decoherence of a driven superconducting qubit}, volume={26}, ISSN={2331-7019}, url={http://dx.doi.org/10.1103/3q5z-tk7c}, DOI={10.1103/3q5z-tk7c}, number={1}, journal={Physical Review Applied}, publisher={American Physical Society (APS)}, author={Kishmar, Mykola and Kurilovich, Pavel D. and Klots, Andrey and Connolly, Thomas and Aleiner, Igor L. and Kurilovich, Vladislav D.}, year={2026}, month=July }

Metadata:Crossref

Access the Paper

This paper is available from its original source. Click below to access the PDF.

Open PDF

License: https://creativecommons.org/licenses/by/4.0/

Quasiparticle-induced decoherence of a driven superconducting qubit

Abstract

Topics

Keywords

Table of Contents

Knowls

Knowl 1 — Single-Photon Microwave-Assisted Quasiparticle Relaxation Rate in Flux-Tunable Transmons

Knowl 2 — Multi-Photon Cooper-Pair Breaking Transition Rates in Driven Superconducting Qubits

Knowl 3 — Two-Photon-Assisted Quasiparticle Relaxation Rate and Interference Cancellation at Zero Flux

Knowl 4 — Microwave-Assisted Quasiparticle-Induced Qubit Excitation Rates and Resonant Enhancement

Knowl 5 — Bounds on Superconducting Qubit Readout and Gate Fidelity Imposed by Quasiparticles

Knowl 6 — Performance Limit on High-Frequency Dispersive Readout from Multi-Photon Pair Breaking

Knowl 7 — Hamiltonian Model for a Driven Transmon with Quasiparticles and Microwave-Assisted Tunneling

Knowl 8 — Diagrammatic Perturbation Theory for Multi-Photon Quasiparticle-Qubit Interactions

References

Citation

BibTeX

Access the Paper