We propose to achieve and enhance the magnon blockade effect in an optomechanical-magnetic system based on a quantum destructive interference mechanism between three indirect transition pathways. By introducing a degenerate parametric amplifier, we analytically obtain the optimal parametric gain and phase for achieving the magnon blockade. Under the optimized parameter conditions, the driving detunings of cavity and magnon modes can be flexibly controlled to achieve the smallest second-order magnon correlation function. Moreover, the magnon blockade can exhibit fascinating features by proper driving detuning and weaker driving strength. Our scheme combines the benefits of destructive interference-induced magnon blockade and energy-level anharmonicity-induced magnon blockade, which results in a reduction of equal-time second-order magnon correlation while simultaneously avoiding time-delay second-order magnon correlation with rapid oscillation. Our work provides an alternative and experimentally feasible platform for manipulating few-magnon states and generating single-magnon sources.
We propose to achieve and enhance the magnon blockade effect in an optomechanical-magnetic system based on a quantum destructive interference mechanism between three indirect transition pathways. By introducing a degenerate parametric amplifier, we analytically obtain the optimal parametric gain and phase for achieving the magnon blockade. Under the optimized parameter conditions, the driving detunings of cavity and magnon modes can be flexibly controlled to achieve the smallest second-order magnon correlation function. Moreover, the magnon blockade can exhibit fascinating features by proper driving detuning and weaker driving strength. Our scheme combines the benefits of destructive interference-induced magnon blockade and energy-level anharmonicity-induced magnon blockade, which results in a reduction of equal-time second-order magnon correlation while simultaneously avoiding time-delay second-order magnon correlation with rapid oscillation. Our work provides an alternative and experimentally feasible platform for manipulating few-magnon states and generating single-magnon sources.
We propose to achieve and enhance the unconventional magnon blockade effect, based on a quantum destructive interference mechanism in an op to mechanical magnetic system composed of a rotating cavity and a yttrium irongarnet (YIG) sphere. We introduce a degenerate parametric amplifier and derive the optimal parametric gain and phase to achieve magnon blockade analytically. By tuning the system parameters (weak coupling) and the driving detuning of the cavity and magnon modes, we achieve the smallest second-order magnon correlation function. The optomechanical cavity couples to the YIG sphere by magnetic dipole interaction. We achieve unconventional magnon blockade effects when the cavity is driven from a clockwise or counterclockwise direction. We introduce a new feature that combines the impact of destructive interference and energy-level anharmonicity to achieve magnon blockade. The equal-time second-order magnon correlation avoids time delay and rapid oscillation. In the input end of the system, two photons drive, and complete quantum destructive interference. This study opens a new window for physical applications, including the generation of single magnon sources, Quantum sensing, and Quantum simulation. Experimentally, we can control quantum noise and amplify the signal using parametric amplification.
Abstract Magnon blockade is one of the effective methods for realizing single magnon sources which have great potential application in quantum information processing and quantum computing. To enhance single-magnon blockade effect, we introduce a two-magnon driving to the magnomechanical system, which is used to form the multipath destructive interference. Our result shows that both the conventional magnon blockade (CMB) and unconventional magnon blockade (UMB) can be achieved due to nonlinear term of the magnon-mechanical oscillator and magnetic parametric amplification term(MPA) induced by two-magnon driving. By setting certain parameters of MPA, we combine the effect of CMB and UMB. As a result, the single-magnon blockade effect is enhanced, and the disadvantage of rapid oscillations of the time-delay second-order correlation function g (2)(τ) with UMB is overcome, which makes high time resolution not necessary in the detection of second-order correlation function.
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.
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.
Abstract We study the magnon antibunching effect in the magnon-qubit coupling system under the joint action of coherent and parametric drives. The analysis and numerical results reveal the conventional magnon blockade (CMB) caused by the anharmonic level splitting induced by strong magnon–qubit coupling and the unconventional magnon blockade (UMB) induced by multipath destructive interference. Notably, in the strong-coupling regime, substituting the CMB condition into the optimal UMB condition yields a phase-tuned CMB-constrained UMB condition, which simultaneously realizes strong magnon antibunching and a high single-magnon occupation probability. This combines the high brightness afforded by CMB with the high purity provided by UMB. Furthermore, in the weak-coupling regime, coordinated tuning of the phase, detuning, parametric drive, and coupling strength induces destructive interference among distinct excitation pathways, thereby yielding the UMB effect. Importantly, even in the zero-coupling limit, the additional channel provided by the parametric drive can sustain this blockade. This flexibility removes the reliance on stringent strong-coupling constraints, offering a viable route toward tunable strong magnon antibunching.
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.