论文标题
Cecoin $ _5 $的旋转共振模式的性质
Nature of the spin resonance mode in CeCoIn$_5$
论文作者
论文摘要
自旋 - 裂开介导的非常规超导性可以在磁性的边界中出现，其中具有超导顺序参数，该参数会在动量空间中改变符号。由于大多数探针不是相敏感的，因此检测这种标志变换在实验上具有挑战性。通过假设SRM是旋转激发的结合态，通常将来自非弹性中子散射的自旋共振模式（SRM）视为符号改变超导级参数的强相位敏感证据。在这里，我们表明，对于沉重的费米昂超导体cecoin $ _5 $，其SRM违反了对旋转激发界面状态的期望，并且不是签名变化的超导性的表现。取而代之的是，Cecoin $ _5 $中的SRM可能是由于其靠近磁量子关键性，因此在超导状态下的阻尼到类似镁的模式。我们的发现强调了需要更严格的测试，即SRM是否是自旋优异的，当它们使用它们的存在来证明签名改变超导性。
Spin-fluctuation-mediated unconventional superconductivity can emerge at the border of magnetism, featuring a superconducting order parameter that changes sign in momentum space. Detection of such a sign-change is experimentally challenging, since most probes are not phase-sensitive. The observation of a spin resonance mode (SRM) from inelastic neutron scattering is often seen as strong phase-sensitive evidence for a sign-changing superconducting order parameter, by assuming the SRM is a spin-excitonic bound state. Here, we show that for the heavy fermion superconductor CeCoIn$_5$, its SRM defies expectations for a spin-excitonic bound state, and is not a manifestation of sign-changing superconductivity. Instead, the SRM in CeCoIn$_5$ likely arises from a reduction of damping to a magnon-like mode in the superconducting state, due to its proximity to magnetic quantum criticality. Our findings emphasize the need for more stringent tests of whether SRMs are spin-excitonic, when using their presence to evidence sign-changing superconductivity.
