论文标题
通过连贯的完美吸收引起的腔镁镁非线性的检测敏感性增强了镁KERR非线性的敏感性
Detection sensitivity enhancement of magnon Kerr nonlinearity in cavity magnonics induced by coherent perfect absorption
论文作者
论文摘要
我们展示了如何增强型镁镁中的镁kerr非线性（MKN）的检测灵敏度。所考虑的腔体磁通系统由一个三维微波腔组成，其中包含两个Yttrium Iron Garnet（YIG）球，其中两个磁杆模式（一个具有MKN，而另一个是线性的），而YIG球体则同时将其耦合到微层层光子上。为了获得空腔模式的有效增益，我们将两个输入场馈入空腔。通过选择适当的参数，会发生两个输入场的连贯的完美吸收，并且可以通过有效的非热汉密尔顿式型腔体系统来描述腔体磁通系统。在伪 - 温米特的条件下，有效的哈密顿量可以容纳三阶的特殊点（EP3），其中汉密尔顿合并的三个特征值分为一个。当MKN引起的镁频移$δ_K$要比腔频谱中峰的线宽$γ$小得多（即$δ_K\llγ$）时，可以通过EP3扩增镁频移，这可以通过EP3进行探测，这可以通过输出谱的输出光谱进行探测。我们提出的方案提供了一种替代方法来测量该区域的MKN $δ_K\llγ$，并且在基于MKN的低功率非线性设备时具有潜在的应用。
We show how to enhance the detection sensitivity of magnon Kerr nonlinearity (MKN) in cavity magnonics. The considered cavity-magnon system consists of a three-dimensional microwave cavity containing two yttrium iron garnet (YIG) spheres, where the two magnon modes (one has the MKN, while the other is linear) in YIG spheres are simultaneously coupled to microwave photons. To obtain the effective gain of the cavity mode, we feed two input fields into the cavity. By choosing appropriate parameters, the coherent perfect absorption of the two input fields occurs, and the cavity-magnon system can be described by an effective non-Hermitian Hamiltonian. Under the pseudo-Hermitian conditions, the effective Hamiltonian can host the third-order exceptional point (EP3), where the three eigenvalues of the Hamiltonian coalesce into one. When the magnon frequency shift $Δ_K$ induced by the MKN is much smaller than the linewidths $Γ$ of the peaks in the transmission spectrum of the cavity (i.e., $Δ_K\ll Γ$), the magnon frequency shift can be amplified by the EP3, which can be probed via the output spectrum of the cavity. The scheme we present provides an alternative approach to measure the MKN in the region $Δ_K\ll Γ$ and has potential applications in designing low-power nonlinear devices based on the MKN.
