Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2303.13823 · Physical Review A

Magnon blockade in magnon-qubit systems

Zhu-yao Jin, Jun Jing

Published Nov 1, 2023• 29 citations
arXivHTMLPDF

Abstract

A hybrid system established by the direct interaction between a magnon mode and a superconducting transmon qubit is used to realize a high-degree blockade for magnon. It is a fundamental way toward quantum manipulation at the level of a single magnon and preparation of single magnon sources. Through weakly driving the magnon and probing the qubit, our magnon-blockade proposal can be optimized when the transversal coupling strength between the magnon and qubit is equivalent to the detuning of the qubit and the probing field or that of the magnon and the driving field. Under this condition, the equal-time second-order correlation function ${g}^{(2)}(0)$ can be analytically minimized when the probing intensity is about three times the driving intensity. Moreover, the magnon blockade could be further enhanced by proper driving intensity and system decay rate, whose magnitudes outrange the current systems of cavity QED and cavity optomechanics. In particular, the correlation function achieves ${g}^{(2)}(0)\ensuremath{\sim}{10}^{\ensuremath{-}7}$, about two orders lower than that for the photon blockade in cavity optomechanics. Also, we discuss the effects on ${g}^{(2)}(0)$ from thermal noise and the extra longitudinal interaction between the magnon and qubit. Our optimized conditions for blockade are found to persist in these nonideal situations.

DOI
10.1103/physreva.108.053702

Related papers

Stabilizing a single-magnon state by optimizing magnon blockade

Zhu-yao Jin, Jun Jing

A stable and high-quality single-magnon state is desired by the single-magnon source for quantum-information application with a macroscopic spin system. We consider a hybrid system where a magnon mode is directly coupled to a nonresonant superconducting qubit via the exchange interaction. The magnon and qubit are under the driving and probing fields with the same frequency, respectively. We find that the single-magnon probability ${P}_{1}$ can be maximized when the product of the magnon-driving field detuning and the qubit-probing field detuning is equivalent to the square of the magnon-qubit coupling strength, ${\mathrm{\ensuremath{\Delta}}}_{q}{\mathrm{\ensuremath{\Delta}}}_{m}\ensuremath{\approx}{J}^{2}$. Then, the double-magnon probability ${P}_{2}$ can be minimized by tuning the ratio of the probing intensity to the driving intensity and the relative phase between the two fields. Under these optimized conditions with accessible strong driving intensity and low decay rate, strong magnon blockade gives rise to a stable single-magnon state with a high quality. It features a large brightness (the single-magnon probability) ${P}_{1}\ensuremath{\approx}0.40$ and a high purity (the equal-time second-order correlation function) ${g}^{(2)}(0)\ensuremath{\sim}{10}^{\ensuremath{-}5}$. The two indicators as a whole prevail over the existing results for photon, phonon, and magnon modes with respect to a stable single-quantum state. The optimized conditions with a scalable modification ${\mathrm{\ensuremath{\Delta}}}_{q}{\mathrm{\ensuremath{\Delta}}}_{m}\ensuremath{\approx}N{J}^{2}$ apply to the situation when one focuses on any one of the $N$ magnon modes that are simultaneously coupled to a common qubit.

arXiv:2401.01590•Physical Review A•Jul 24, 2024•17 citations

Magnon blockade in spin-magnon systems with frequency detuning

Sheng Zhao, Ya-long Ren, Xin‐Lei Hei +2 more

Magnon blockade is a physical mechanism for the preparation of a single-magnon source, which has important applications in quantum information processing. Here we propose a scheme for generating an optimal magnon blockade in the spin-magnon quantum system. By introducing frequency detuning between the magnon and the spin qubit of the NV center, the conventional magnon blockade and the unconventional magnon blockade can be obtained under both strong and weak coupling, relaxing the requirements for coupling strength. Moreover, the conventional and unconventional magnon blockade can occur simultaneously when both the magnon and the spin qubit are driven. This allows the equal-time second-order correlation function to reach $10^{-8}$, about five orders of magnitude lower than that in previous works. Additionally, the time-delayed second-order correlation function avoids oscillation. Our study demonstrates the impact of frequency detuning on the magnon blockade and proposes methods to enhance the magnon blockade and relax the requirements for coupling strength through frequency detuning.

arXiv:2505.21320•Physical Review A•Jun 23, 2025•6 citations

Magnon blockade with skyrmion qubit-magnon coupling in a hybrid quantum system

Si-Tong Jin, Shi-Wen He, Zi‐Long Yang +2 more

Abstract Magnon blockade (MB) is a fundamental quantum phenomenon for generating single-magnon states, and has gradually become one of the candidates for quantum information processing. We extend existing blockade optimization schemes to a hybrid system consisting of a YIG micromagnet and a skyrmion, and propose a theoretical scheme for achieving MB on this platform. Under weak magnon probing and external driving of the skyrmion qubit, the second-order correlation function is analytically derived, and the optimal parameter conditions for both conventional and unconventional MB are identified. By appropriately adjusting the intensities of the driving and probing fields, the MB effect is significantly enhanced, multi-magnon excitations are effectively suppressed, and strong antibunching is achieved. Further analysis reveals that MB originates from two distinct physical mechanisms: conventional blockade induced by anharmonicity of the energy level structure, and unconventional blockade arising from quantum interference between different transition paths. On this platform, the two mechanisms coexist and can be synergistically controlled, and their cooperation yields a blockade effect superior to that of either mechanism alone. This work thus provides a feasible theoretical scheme for the effective manipulation of MB effects.

arXiv:2412.11359•Journal of Physics B Atomic Molecular and Optical Physics•Aug 4, 2026•0 citations

Magnon blockade in a hybrid ferromagnet-superconductor quantum system

Zeng‐Xing Liu, Hao Xiong, Ying Wu

The implementation of a single magnon level quantum manipulation is one of the fundamental targets in quantum magnetism with a significant practical relevance for precision metrology, quantum information processing, and quantum simulation. Here we demonstrate theoretically the feasibility of using a hybrid ferromagnet-superconductor quantum system to prepare a single magnon source based on magnon blockade effects. By numerically solving the quantum master equation, we show that the second-order correlation function of the magnon mode depends crucially on the relation between the qubit-magnon coupling strength and the driving detuning, and simultaneously signatures of the magnon blockade appear only under quite stringent conditions of a cryogenic temperature. In addition to providing perception into the quantum phenomena of magnon, the study of magnon blockade effects will help to develop novel technologies for exploring the undiscovered magnon traits at the quantum level and may find applications in designing single magnon emitters.

arXiv:1910.03738•Physical review. B./Physical review. B•Oct 17, 2019•206 citations

Nonclassical magnon pair generation and Cauchy-Schwarz inequality violation

Yaqi Fan, Jiahua Li, Ying Wu

We theoretically propose a magnon-based superconducting qubit hybrid system containing two ferromagnetic yttrium iron garnets (YIGs) and one superconducting qubit, demonstrating that this hybrid quantum system is feasible in achieving the unconventional two-mode magnon blockade and generating the quantum correlated magnon pairs. Through the virtual-photon excitation mediated by the same cavity mode, the effective couplings can be established not only between the Kittel modes and the qubit, but also between the two Kittel modes. We characterize the magnon blockade by utilizing the equal-time second-order correlation functions and impose a constraint on the correlations between the two Kittel modes by introducing the Cauchy-Schwarz inequality (CSI). In the weak qubit-magnon coupling regime, our results indicate the following: (i) Under the scenario of the resonance couplings, the ratio of driving strengths and the ratio of coupling strengths between the two Kittel modes and the cavity mode can be employed to control and regulate the magnon blockade and the violation of the CSI. Not only the two Kittel modes can achieve the unconventional magnon antibunching effects simultaneously, but also the correlations between them violate the classical CSI. It is important to note that when the degrees of both the antibunching effects for the two Kittel modes and the anticorrelation between them reach their highest levels simultaneously, the correlations happen not to violate the CSI. But our proposal offers a feasible route for preparing a high-quality single-magnon source. (ii) Under the scenario of the out-of-resonance couplings, by adjusting the frequency detunings between the first Kittel mode and the second Kittel mode as well as the qubit, the quantum correlated two-mode magnon pairs can be obtained. (iii) Finally, it is found that the magnon antibunching effect of the second Kittel mode is robust against the dissipation ratio between the two Kittel modes. These results illustrate how to optimally choose the parameters to realize nonclassical magnon pair generation and CSI violation. The hybrid YIG quantum system we propose here holds the potential in the development of efficient microwave single-magnon sources and quantum magnon-magnon pairs required in future quantum information processing tasks.

Physical Review A•Nov 21, 2023•8 citations

Magnon Blockade in a Hybrid Magnon‐Superconducting Qubit System

Xinxin Zheng, Mei‐Rong Wei, Qi Guo

ABSTRACT We propose a scheme to realize magnon blockade in a hybrid system composed of a transmon‐type superconducting qubit directly coupled to the magnon mode of a single‐crystalline yttrium‐iron‐garnet sphere. By applying two‐tone driving to the qubit, we engineer an effective Hamiltonian for the magnon mode including both single‐magnon and two‐magnon interaction. Due to the destructive interference between two transition paths, the two‐magnon excitation is suppressed, and thus the unconventional magnon blockade can be achieved. We also demonstrate that the intrinsic anharmonicity of the qubit can be transferred to the magnon mode through their coherent hybridization, but this anharmonicity has almost no influence on the blockade effect. Through solving the second‐order correlation function analytically and numerically, we show that the scheme can be realized under experimentally feasible conditions and remains robust against system dissipations and environment temperature. Therefore, the presented work provides a viable path toward generating single‐magnon sources and advancing quantum information processing with magnonic platforms.

Annalen der Physik•Mar 30, 2026•0 citations
A hybrid system established by the direct interaction between a magnon mode and a superconducting transmon qubit is used to realize a high-degree blockade for magnon. It is a fundamental way toward quantum manipulation at the level of a single magnon and preparation of single magnon sources. Through weakly driving the magnon and probing the qubit, our magnon-blockade proposal can be optimized when the transversal coupling strength between the magnon and qubit is equivalent to the detuning of the qubit and the probing field or that of the magnon and the driving field. Under this condition, the equal-time second-order correlation function g(2)(0){g}^{(2)}(0)g(2)(0) can be analytically minimized when the probing intensity is about three times the driving intensity. Moreover, the magnon blockade could be further enhanced by proper driving intensity and system decay rate, whose magnitudes outrange the current systems of cavity QED and cavity optomechanics. In particular, the correlation function achieves g(2)(0)\ensuremath∼10\ensuremath−7{g}^{(2)}(0)\ensuremath{\sim}{10}^{\ensuremath{-}7}g(2)(0)\ensuremath∼10\ensuremath−7, about two orders lower than that for the photon blockade in cavity optomechanics. Also, we discuss the effects on g(2)(0){g}^{(2)}(0)g(2)(0) from thermal noise and the extra longitudinal interaction between the magnon and qubit. Our optimized conditions for blockade are found to persist in these nonideal situations.
A stable and high-quality single-magnon state is desired by the single-magnon source for quantum-information application with a macroscopic spin system. We consider a hybrid system where a magnon mode is directly coupled to a nonresonant superconducting qubit via the exchange interaction. The magnon and qubit are under the driving and probing fields with the same frequency, respectively. We find that the single-magnon probability P1{P}_{1}P1​ can be maximized when the product of the magnon-driving field detuning and the qubit-probing field detuning is equivalent to the square of the magnon-qubit coupling strength, ${\mathrm{\ensuremath{\Delta}}}_{q}{\mathrm{\ensuremath{\Delta}}}_{m}\ensuremath{\approx}{J}^{2}$. Then, the double-magnon probability P2{P}_{2}P2​ can be minimized by tuning the ratio of the probing intensity to the driving intensity and the relative phase between the two fields. Under these optimized conditions with accessible strong driving intensity and low decay rate, strong magnon blockade gives rise to a stable single-magnon state with a high quality. It features a large brightness (the single-magnon probability) ${P}_{1}\ensuremath{\approx}0.40$ and a high purity (the equal-time second-order correlation function) ${g}^{(2)}(0)\ensuremath{\sim}{10}^{\ensuremath{-}5}$. The two indicators as a whole prevail over the existing results for photon, phonon, and magnon modes with respect to a stable single-quantum state. The optimized conditions with a scalable modification ${\mathrm{\ensuremath{\Delta}}}_{q}{\mathrm{\ensuremath{\Delta}}}_{m}\ensuremath{\approx}N{J}^{2}$ apply to the situation when one focuses on any one of the NNN magnon modes that are simultaneously coupled to a common qubit.
Magnon blockade is a physical mechanism for the preparation of a single-magnon source, which has important applications in quantum information processing. Here we propose a scheme for generating an optimal magnon blockade in the spin-magnon quantum system. By introducing frequency detuning between the magnon and the spin qubit of the NV center, the conventional magnon blockade and the unconventional magnon blockade can be obtained under both strong and weak coupling, relaxing the requirements for coupling strength. Moreover, the conventional and unconventional magnon blockade can occur simultaneously when both the magnon and the spin qubit are driven. This allows the equal-time second-order correlation function to reach 10−810^{-8}10−8, about five orders of magnitude lower than that in previous works. Additionally, the time-delayed second-order correlation function avoids oscillation. Our study demonstrates the impact of frequency detuning on the magnon blockade and proposes methods to enhance the magnon blockade and relax the requirements for coupling strength through frequency detuning.
Abstract Magnon blockade (MB) is a fundamental quantum phenomenon for generating single-magnon states, and has gradually become one of the candidates for quantum information processing. We extend existing blockade optimization schemes to a hybrid system consisting of a YIG micromagnet and a skyrmion, and propose a theoretical scheme for achieving MB on this platform. Under weak magnon probing and external driving of the skyrmion qubit, the second-order correlation function is analytically derived, and the optimal parameter conditions for both conventional and unconventional MB are identified. By appropriately adjusting the intensities of the driving and probing fields, the MB effect is significantly enhanced, multi-magnon excitations are effectively suppressed, and strong antibunching is achieved. Further analysis reveals that MB originates from two distinct physical mechanisms: conventional blockade induced by anharmonicity of the energy level structure, and unconventional blockade arising from quantum interference between different transition paths. On this platform, the two mechanisms coexist and can be synergistically controlled, and their cooperation yields a blockade effect superior to that of either mechanism alone. This work thus provides a feasible theoretical scheme for the effective manipulation of MB effects.
The implementation of a single magnon level quantum manipulation is one of the fundamental targets in quantum magnetism with a significant practical relevance for precision metrology, quantum information processing, and quantum simulation. Here we demonstrate theoretically the feasibility of using a hybrid ferromagnet-superconductor quantum system to prepare a single magnon source based on magnon blockade effects. By numerically solving the quantum master equation, we show that the second-order correlation function of the magnon mode depends crucially on the relation between the qubit-magnon coupling strength and the driving detuning, and simultaneously signatures of the magnon blockade appear only under quite stringent conditions of a cryogenic temperature. In addition to providing perception into the quantum phenomena of magnon, the study of magnon blockade effects will help to develop novel technologies for exploring the undiscovered magnon traits at the quantum level and may find applications in designing single magnon emitters.
We theoretically propose a magnon-based superconducting qubit hybrid system containing two ferromagnetic yttrium iron garnets (YIGs) and one superconducting qubit, demonstrating that this hybrid quantum system is feasible in achieving the unconventional two-mode magnon blockade and generating the quantum correlated magnon pairs. Through the virtual-photon excitation mediated by the same cavity mode, the effective couplings can be established not only between the Kittel modes and the qubit, but also between the two Kittel modes. We characterize the magnon blockade by utilizing the equal-time second-order correlation functions and impose a constraint on the correlations between the two Kittel modes by introducing the Cauchy-Schwarz inequality (CSI). In the weak qubit-magnon coupling regime, our results indicate the following: (i) Under the scenario of the resonance couplings, the ratio of driving strengths and the ratio of coupling strengths between the two Kittel modes and the cavity mode can be employed to control and regulate the magnon blockade and the violation of the CSI. Not only the two Kittel modes can achieve the unconventional magnon antibunching effects simultaneously, but also the correlations between them violate the classical CSI. It is important to note that when the degrees of both the antibunching effects for the two Kittel modes and the anticorrelation between them reach their highest levels simultaneously, the correlations happen not to violate the CSI. But our proposal offers a feasible route for preparing a high-quality single-magnon source. (ii) Under the scenario of the out-of-resonance couplings, by adjusting the frequency detunings between the first Kittel mode and the second Kittel mode as well as the qubit, the quantum correlated two-mode magnon pairs can be obtained. (iii) Finally, it is found that the magnon antibunching effect of the second Kittel mode is robust against the dissipation ratio between the two Kittel modes. These results illustrate how to optimally choose the parameters to realize nonclassical magnon pair generation and CSI violation. The hybrid YIG quantum system we propose here holds the potential in the development of efficient microwave single-magnon sources and quantum magnon-magnon pairs required in future quantum information processing tasks.
ABSTRACT We propose a scheme to realize magnon blockade in a hybrid system composed of a transmon‐type superconducting qubit directly coupled to the magnon mode of a single‐crystalline yttrium‐iron‐garnet sphere. By applying two‐tone driving to the qubit, we engineer an effective Hamiltonian for the magnon mode including both single‐magnon and two‐magnon interaction. Due to the destructive interference between two transition paths, the two‐magnon excitation is suppressed, and thus the unconventional magnon blockade can be achieved. We also demonstrate that the intrinsic anharmonicity of the qubit can be transferred to the magnon mode through their coherent hybridization, but this anharmonicity has almost no influence on the blockade effect. Through solving the second‐order correlation function analytically and numerically, we show that the scheme can be realized under experimentally feasible conditions and remains robust against system dissipations and environment temperature. Therefore, the presented work provides a viable path toward generating single‐magnon sources and advancing quantum information processing with magnonic platforms.