Fig. 1. Intermetallic compounds with lanthanides or actinides form the majority of heavy fermion materials.重费米子材料大多是含有镧系或锕系元素的金属间化合物

Fig. 2. (a) A schematic illustration of the crystal structure of CeCu₂Si₂; (b) and (c) evidences for superconductivity in CeCu₂Si₂ from resistivity and heat capacity, respectively^[3]; (d) temperature-pressure phase diagram of CeCu₂Si₂ and CeCu₂(Si_1–xGe_x)₂, suggesting two separate superconducting domes^[8]. (a) CeCu₂Si₂结构示意图; (b), (c)超导电性在电阻和比热上的体现^[3]; (d) 压力诱导的双超导相^[8]

Fig. 3. (a) Schematic illustrations of crystalline structures in Ce_nM_mIn_3n+2m(M = Co, Rh, Ir; n, m are integers) (M = Rh for example); (b) a schematic pressure-temperature phase diagram of CeIn₃ and CeRhIn₅^[24]. (a) Ce_nM_mIn_3n+2m(M = Co, Rh, Ir; n, m为整数)体系的晶体结构 (以M = Rh为例); (b) CeIn₃和CeRhIn₅的压力-温度相图示意图^[24]

Fig. 4. (a) Magnetic field (B)-temperature (T) phase diagram of YbRh₂Si₂ and YbRh₂(Si_0.95Ge_0.05)₂^[43]; (b) B-T phase diagram of YbRh₂Si₂ at lower temperature, suggesting a superconducting region^[47]. (a) YbRh₂Si₂和YbRh₂(Si_0.95Ge_0.05)₂的B-T相图^[43]; (b) 极低温下的YbRh₂Si₂的B-T相图^[47]

Fig. 5. (a), (b) Schematic illustrations of the crystalline structure of UBe₁₃ and UPt₃, respectively; (c) superconducting phase diagram of UBe₁₃ as a function of Th-doping^[53]; (d) magnetic field–temperature superconducting phase diagram of UPt₃^[58]. (a) UBe₁₃结构示意图; (b) UPt₃结构示意图; (c) Th掺杂的UBe₁₃相图^[53]; (d) UPt₃的超导相图^[58]

Fig. 6. Temperature dependence of the magnetic penetration depth Δλ^[10] (a) and specific heat C_e/T^[11](b) of CeCu₂Si₂, both showing a fully gapped behavior at the lowest temperature. 重费米子超导体CeCu₂Si₂的(a)磁场穿透深度Δλ^[10]和(b)低温比热系数C_e/T^[11], 两者在低温都呈指数衰减

Fig. 7. Heavy fermion superconductors and quantum phase diagrams: (a) CePd₂Si_2, superconductivity (SC) near an antiferromagnetic quantum critical point(QCP)^[19]; (b) UCoGe, SC near a ferromagnetic QCP^[87]; (c) PrTi₂Al_20, SC coexists with multipolar order and gets enhanced near its QCP^[89]; (d) β-YbAlB₄, SC far away from an antiferromagnetic QCP^[90]. 重费米子超导体超导相和量子相变　(a) CePd₂Si_2, 超导出现在反铁磁量子临界点附近^[19]; (b) UCoGe, 超导出现在铁磁量子相变附近^[87]; (c) PrTi₂Al_20, 超导与多极矩序^[89]; (d) β-YbAlB_4, 超导远离反铁磁量子临界点^[90]

Fig. 8. Schematic phase diagrams for itinerant quantum critical point (QCP) (a) and local QCP (b), respectively, proposed in one theoretical model. The x-axis denotes nonthermal tuning parameters δ, y-axis is the temperature T. T_N is the antiferromagnetic ordering temperature, denotes the volume change of Fermi surface and T₀ is the temperature regime where kondo lattice forms^[99]. 巡游量子临界点(a)和局域量子临界点(b)的理论相图　图中的横坐标是非热力的调控参量δ, 纵坐标表示温度T, 调控参量δ可以调节RKKY作用和Kondo作用的相对强度; 图(a)显示量子临界点伴随近藤效应的塌陷, 导致费米面在此发生跳变; 而在图(b)中, 近藤效应发生在反铁磁态内部, 费米面在量子临界点连续变化; T_N代表反铁磁转变温度, T_FL表示费米液体的温度上限, 标记小费米面到大费米面的转变, T₀代表近藤晶格形成的过渡区间^[99]

Fig. 9. Experimental phase diagram of CeRhIn₅ tuned by pressure^[100] (a) and magnetic field^[35] (b); (c) the proposed zero-temperature pressure-field global phase diagram^[35]. CeRhIn₅在(a)压力^[100]和(b) 磁场调制下的相图^[35]; (c) 可能的零温压力-磁场相图^[35]

Fig. 10. (a) Temperature dependence of resistivity for a possible topological Kondo insulator SmB₆, where a clear plateau is observed at low temperature^[116]; (b) band inversion and surface Dirac cone of SmB₆, from band-structure calculation^[128]. (a) 拓扑近藤绝缘体SmB₆的电阻随温度变化测量结果^[116], 在低温, 电阻的上升趋势逐渐饱和, 形成一个平台; (b) 能带计算表明, SmB₆的能带结构中存在能带反转, 从而导致了表面狄拉克锥的出现^[128]

Fig. 11. Topological properties of the low temperature heavy fermion state in YbPtBi^[133]: (a) T³-behavior of the low temperature specific heat C_p/T in different fields; (b) topological Hall effect at low temperatures. YbPtBi在低温重费米子态的拓扑性质^[133] 　(a) 电子比热C_p正比于温度T的三次方; (b) 拓扑霍尔效应

Fig. 12. (a) Pressure-temperature phase diagram of URu₂Si₂^[146]; (b) magnetic field- temperature phase diagram of CePdAl^[150]; (c) Q-phase of CeCoIn₅, by neutron scattering measurements^[151]. (a) URu₂Si₂材料在压力下的相图^[146], 隐藏序相逐渐被抑制, 转变为反铁磁序, 同时超导相消失; (b) CePdAl材料的磁场-温度相图^[150], 在某一磁场区间内, 比热测量结果表明其熵出现极大增加; (c) CeCoIn₅中子散射结果表明其超导上临界磁场附近存在一个特殊的Q相^[151]