Solid State Physics Laboratory, Department of Physics, ETH Zurich, CH-8093 Zurich, Switzerland.
National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr, Tallahassee, Florida 32310, USA.
Nat Commun. 2015 Mar 23;6:6663. doi: 10.1038/ncomms7663.
Strong electron correlations lead to a variety of distinct ground states, such as magnetism, charge order or superconductivity. Understanding the competitive or cooperative interplay between neighbouring phases is an outstanding challenge in physics. CeRhIn₅ is a prototypical example of a heavy-fermion superconductor: it orders anti-ferromagnetically below 3.8 K, and moderate hydrostatic pressure suppresses the anti-ferromagnetic order inducing unconventional superconductivity. Here we show evidence for a phase transition to a state akin to a density wave (DW) under high magnetic fields (>27 T) in high-quality single crystal microstructures of CeRhIn₅. The DW is signalled by a hysteretic anomaly in the in-plane resistivity accompanied by non-linear electrical transport, yet remarkably thermodynamic measurements suggest that the phase transition involves only small portions of the Fermi surface. Such a subtle order might be a common feature among correlated electron systems, reminiscent of the similarly subtle charge DW state in the cuprates.
强电子相关导致了多种不同的基态，如磁性、电荷有序或超导性。理解相邻相之间的竞争或合作相互作用是物理学中的一个突出挑战。CeRhIn₅ 是重费米子超导体的典型例子：它在 3.8K 以下呈反铁磁有序，适度的静水压力抑制反铁磁有序，诱导非常规超导性。在这里，我们在 CeRhIn₅ 的高质量单晶微结构中，在高磁场（>27T）下，证明了类似于密度波（DW）的状态的相变存在的证据。DW 由面内电阻率的滞后异常以及非线性输运信号指示，但引人注目的热力学测量表明，相变仅涉及费米面的小部分。这种微妙的有序可能是关联电子系统的共同特征，类似于铜酸盐中类似的微妙电荷 DW 态。
