相关论文: Signatures of quantum criticality in hole-doped an…
In the physics of condensed matter, quantum critical phenomena and unconventional superconductivity are two major themes. In electron doped cuprates, the low upper critical field allows one to study the putative QCP at low temperature and…
KFe2As2 single crystals are studied using specific-heat, high-resolution thermal-expansion, magnetization, and magnetostriction measurements. The magnetization and magnetostriction data provide clear evidence for strong Pauli limiting…
A series of high quality NaFe$_{1-x}$Cu$_x$As single crystals has been grown by a self-flux technique, which were systematically characterized via structural, transport, thermodynamic, and high pressure measurements. Both the structural and…
We report the structural, magnetic and electronic transport properties of SrFe$_{2-x}$Cu$_x$As$_2$ single crystals grown by self-flux technique. SrCu$_2$As$_2$ and SrFe$_2$As$_2$ both crystallize in ThCr$_2$Si$_2$-type (122-type) structure…
Single crystals of Ba(Fe$_{1-x}$Ru$_x$)$_2$As$_2$, $x<0.37$, have been grown and characterized by structural, magnetic and transport measurements. These measurements show that the structural/magnetic phase transition found in pure…
We study temperature dependent upper critical field $H_{\rm c2}$ of a SrFe$_{1.85}$Co$_{0.15}$As$_{2}$ single crystal (\textit{T$_c$}=20.2 K) along \textit{ab}-plane and \textit{c}-axis through resistivity measurements up to 50 T. For the…
A remarkable several times increase (up to 10 K) of the superconducting critical temperature Tc has been observed in point contacts created on the base of single crystals AFe$_2$As$_2$ (A = K, Cs, Rb). Possible reasons for such a Tc…
We examine the effects of the low-level substitution of S atoms by C and Si atoms on the superconductivity of H$_3$S with the $Im\bar{3}m$ structure at megabar pressure. The hole doping can fine-tune the Fermi energy to reach the electronic…
We performed systematic thermal conductivity measurements on heavily hole-doped Ba$_{1-x}$K$_x$Fe$_2$As$_2$ single crystals with 0.747 $\leq x \leq$ 0.974. At $x$ = 0.747, the $\kappa_0/T$ is negligible, indicating nodeless superconducting…
The transport properties, upper critical fields, superconducting anisotropy, and critical current density in an iso-valent phosphorus-doped BaFe2As2 single crystal close to optimum doping are investigated in this report. Temperature…
Systematic measurements of the resistivity, heat capacity, susceptibility and Hall coefficient are presented for single crystal samples of the electron-doped superconductor Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$. These data delineate an $x-T$ phase…
Temperature-dependent resistivity is studied in single crystals of iron-arsenide superconductor Na$_{1-\delta}$Fe$_{1-x}$Co$_x$As for electrical current directions along, $\rho_a (T)$, and transverse, $\rho_c (T)$, to the Fe-As layers.…
The specific heat $C(T)$ of BaFe$_2$As$_2$ single crystal, electron-doped Ba$_{0.7}$La$_{0.3}$Fe$_2$As$_2$ and hole-doped Ba$_{0.5}$K$_{0.5}$Fe$_2$As$_2$ polycrystals were measured. For undoped BaFe$_2$As$_2$ single crystal, a very sharp…
The effects of isovalent doping on the superconducting transition temperature Tc in novel 112-type iron arsenide Ca1-xLaxFeAs2 were studied by conducting measurements of electrical resistivity rho and magnetization M. P or Sb doping…
We have investigated the pressure dependence of the superconducting transition temperature $T_{c}$ up to 18 GPa of Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ single crystals ranging from the highly underdoped through the nearly optimally…
Pnictides provide an opportunity to study the effects of quantum criticality in a multi-band high temperature superconductor. Quasiparticle mass divergence near optimal doping, observed in two major classes of high-temperature…
In the hole-doped cuprate superconductors, the superconducting transition temperature $T_c$ exhibits a dome-like feature against the doping rate. By contrast, recent experiments reveal that $T_c$ in the electron-doped systems monotonically…
Here we study the effect of electron doping the kagome superconductor CsV$_3$Sb$_5$. Single crystals and powders of CsV$_3$Sb$_{5-x}$Te$_x$ are synthesized and characterized via magnetic susceptibility, nuclear quadrupole resonance, and…
The effects of planar hole concentration, p, and in-plane disorder, Zn (y), on the DC resistivity, r(T), of sintered samples of Y_{1-x}Ca_xBa_2(Cu_{1-y}Zn_y)_3O_{7-d} were investigated over a wide doping range by changing both the oxygen…
The dependence of the superconducting gaps in epitaxial Ba(Fe_{1-x}Co_{x})_2As_2 thin films on the nominal doping x (0.04 \leq x \leq 0.15) was studied by means of point-contact Andreev-reflection spectroscopy. The normalized conductance…