Topology and stability of the Kondo phase in quark matter
Topology and stability of the Kondo phase in quark matter
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DOI：
10.1103/physrevd.96.014016
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发表时间：
2017-03
影响因子：
5
通讯作者：
S. Yasui;Kei Suzuki;K. Itakura
中科院分区：
文献类型：
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作者：
S. Yasui;Kei Suzuki;K. Itakura
我们研究具有重夸克杂质的轻夸克物质的基态特性。该系统表现出“QCD近藤效应”，其中费米表面附近的轻夸克与重夸克之间的相互作用强度随着轻夸克向费米能量的能量减少而增加，并在费米能量附近的某种尺度上发散，称为近藤尺度。在近藤尺度周围和以下，我们必须以非微扰的方式对待动态。作为处理强耦合状态的典型非微扰方法，我们采用平均场方法，引入凝聚态，近藤凝聚态，代表轻夸克和重夸克之间的混合，并确定近藤凝聚态存在下的基态。我们证明基态是一种拓扑非平凡态，重夸克自旋在动量空间中形成刺猬构型。我们可以定义动量空间中基态波函数的贝里相，该波函数与重夸克位置处的单极子相关。我们还研究了随机相位近似中平均场周围的涨落，并证明了由轻夸克 $h$ 和重夸克 $Q$ 的空穴 $h$ 组成的（类激子）集体激发的存在。
We investigate properties of the ground state of a light quark matter with heavy quark impurities. This system exhibits the "QCD Kondo effect" where the interaction strength between a light quark near the Fermi surface and a heavy quark increases with decreasing energy of the light quark towards the Fermi energy, and diverges at some scale near the Fermi energy, called the Kondo scale. Around and below the Kondo scale, we must treat the dynamics nonperturbatively. As a typical nonperturbative method to treat the strong coupling regime, we adopt a mean-field approach where we introduce a condensate, the Kondo condensate, representing a mixing between a light quark and a heavy quark, and determine the ground state in the presence of the Kondo condensate. We show that the ground state is a topologically non-trivial state and the heavy quark spin forms the hedgehog configuration in the momentum space. We can define the Berry phase for the ground-state wavefunction in the momentum space which is associated with a monopole at the position of a heavy quark. We also investigate fluctuations around the mean field in the random-phase approximation, and show the existence of (exciton-like) collective excitations made of a hole $h$ of a light quark and a heavy quark $Q$.