论文标题
pyrochlore着甲酸盐中的集体磁希格斯激发
Collective magnetic Higgs excitation in a pyrochlore ruthenate
论文作者
论文摘要
标量希格斯型振幅模式在自发对称性的系统中的出现一直是对相变的非常成功的范式描述，其影响范围从高能粒子物理学到低能的凝结物质。在这里，我们在Pyrochlore磁铁ND $ _2 $ ru $ _2 $ _2 $ o $ _7 $ at $ t _ {\ Mathrm {n}} = 147 $ k和$ t^* = 97 $ k中发现了两个连续的高温高相过渡。这种连贯的激发与其他声子不同，与常规磁模式不同，在3 MeV的低能量下稳定。我们将其分配给集体希格斯型振幅模式，该模式涉及ru $ _4 $ tetrahedra的债券能量调制。它与基础晶体结构不兼容的醒目的两倍对称性突出了多个纠缠破碎的对称性的可能性。
The emergence of scalar Higgs-type amplitude modes in systems where symmetry is spontaneously broken has been a highly successful, paradigmatic description of phase transitions, with implications ranging from high-energy particle physics to low-energy condensed matter systems. Here, we uncover two successive high temperature phase transitions in the pyrochlore magnet Nd$_2$Ru$_2$O$_7$ at $T_{\mathrm{N}} = 147$ K and $T^* = 97$ K, that lead to giant phonon instabilities and culminate in the emergence of a highly coherent excitation. This coherent excitation, distinct from other phonons and from conventional magnetic modes, stabilizes at a low energy of 3 meV. We assign it to a collective Higgs-type amplitude mode, that involves bond energy modulations of the Ru$_4$ tetrahedra. Its striking two-fold symmetry, incompatible with the underlying crystal structure, highlights the possibility of multiple entangled broken symmetries.
