Kondo physics from quasiparticle poisoning in Majorana devices
Kondo physics from quasiparticle poisoning in Majorana devices
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马约拉纳装置中准粒子中毒的近藤物理学
DOI：
10.1103/physrevb.93.104524
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发表时间：
2016
影响因子：
3.7
通讯作者：
R. Egger
中科院分区：
文献类型：
--
作者：
S. Plugge;A. Zazunov;E. Eriksson;A. Tsvelik;R. Egger
在这里，我们提出了一个理论分析的准粒子中毒库仑阻塞马约拉纳费米子系统隧道耦合到正常的导电导线。考虑到有限能量准粒子，我们推导出有效低能理论，并提出重整化群分析。我们发现定性的新效果时，一个准粒子态具有非常低的能量是本地化附近的隧道接触。对于M = 2的附加引线，这种“危险”的准粒子中毒过程导致自旋S = 1/2的单通道近藤效应，这可以通过在所有库仑阻塞谷中的特征零偏压异常电导峰来检测。对于两个以上的附加引线，未中毒系统的拓扑近藤效应变得不稳定。强耦合玻色化分析表明，在低能量下，中毒的引线被有效地解耦，因此，对于M > 3，拓扑Kondo不动点重新出现，尽管现在它只涉及M-1个引线。因此，对于M = 3，低能量固定点变得微不足道，对应于去耦引线。
Here, we present a theoretical analysis of quasiparticle poisoning in Coulomb-blockaded Majorana fermion systems tunnel-coupled to normal-conducting leads. Taking into account finite-energy quasiparticles, we derive the effective low-energy theory and present a renormalization group analysis. We find qualitatively new effects when a quasiparticle state with very low energy is localized near a tunnel contact. For M = 2 attached leads, such “dangerous” quasiparticle poisoning processes cause a spin S = 1/2 single-channel Kondo effect, which can be detected through a characteristic zero-bias anomaly conductance peak in all Coulomb blockade valleys. For more than two attached leads, the topological Kondo effect of the unpoisoned system becomes unstable. A strong-coupling bosonization analysis indicates that at low energy the poisoned lead is effectively decoupled and hence, for M > 3, the topological Kondo fixed point re-emerges, though now it involves only M–1 leads. As a consequence, for M = 3, the low-energy fixed point becomes trivial corresponding to decoupled leads.
影响因子：
8.6
作者：
Altland, Alexander;Egger, Reinhold
通讯作者：
Egger, Reinhold
影响因子：
8.6
作者：
Kashuba, Oleksiy;Timm, Carsten
通讯作者：
Timm, Carsten