اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدSpecific heat of robust Nb2PdS5 superconductor
272
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We report specific heat under different magnetic fields for recently discovered quasi-one dimensional Nb2PdS5 superconductor. The studied compound is superconducting below 6 K. Nb2PdS5 is quite robust against magnetic field with dHc/dT of -42 kOe/K. The estimated upper critical field [Hc2(0)] is 190 kOe, clearly surpassing the Pauli-paramagnetic limit of 1.84Tc. Low temperature heat capacity in superconducting state of Nb2PdS5 under different magnetic fields showed s-wave superconductivity with two different gaps. Two quasi-linear slopes in Somerfield-coefficient as a function of applied magnetic field and two band behavior of the electronic heat capacity demonstrate that Nb2PdS5 is a multiband su-perconductor in weak coupling limit with deltagamma/deltaTc=0.9.
قيم البحث
اقرأ أيضاً
Understanding the thermodynamic properties of high-$T_c$ cuprate superconductors is a key step to establish a satisfactory theory of these materials. The electronic specific heat is highly unconventional, distinctly non-BCS, with remarkable doping-de
pendent features extending well beyond $T_c$. The pairon concept, bound holes in their local antiferromagnetic environment, has successfully described the tunneling and photoemission spectra. In this article, we show that the model explains the distinctive features of the entropy and specific heat throughout the temperature-doping phase diagram. Their interpretation connects unambiguously the pseudogap, existing up to $T^*$, to the superconducting state below $T_c$. In the underdoped case, the specific heat is dominated by pairon excitations, following Bose statistics, while with increasing doping, both bosonic excitations and fermionic quasiparticles coexist.
Sn0.8Ag0.2Te is a new superconductor with Tc ~ 2.4 K. The superconducting properties of Sn0.8Ag0.2Te have been investigated by specific heat measurements under magnetic fields. Bulk nature of superconductivity was confirmed from the amplitude of the
specific heat jump at the superconducting transition, and the amplitude is consistent with fully-gapped superconductivity. Upper critical field was estimated from specific heat and electrical resistivity measurements under magnetic fields. The Hall coefficient was positive, suggesting that the Ag acts as a p-type dopant in Sn0.8Ag0.2Te.
The Majorana fermion, which is its own anti-particle and obeys non-abelian statistics, plays a critical role in topological quantum computing. It can be realized as a bound state at zero energy, called a Majorana zero mode (MZM), in the vortex core o
f a topological superconductor, or at the ends of a nanowire when both superconductivity and strong spin orbital coupling are present. A MZM can be detected as a zero-bias conductance peak (ZBCP) in tunneling spectroscopy. However, in practice, clean and robust MZMs have not been realized in the vortices of a superconductor, due to contamination from impurity states or other closely-packed Caroli-de Gennes-Matricon (CdGM) states, which hampers further manipulations of Majorana fermions. Here using scanning tunneling spectroscopy, we show that a ZBCP well separated from the other discrete CdGM states exists ubiquitously in the cores of free vortices in the defect free regions of (Li0.84Fe0.16)OHFeSe, which has a superconducting transition temperature of 42 K. Moreover, a Dirac-cone-type surface state is observed by angle-resolved photoemission spectroscopy, and its topological nature is confirmed by band calculations. The observed ZBCP can be naturally attributed to a MZM arising from this chiral topological surface states of a bulk superconductor. (Li0.84Fe0.16)OHFeSe thus provides an ideal platform for studying MZMs and topological quantum computing.
A high-entropy-alloy-type (HEA-type) superconductor is new category of highly disordered superconductors. Therefore, finding brand-new superconducting characteristics in the HEA-type superconductors would open new avenue to investigate the relationsh
ip between structural disorder and superconductivity. Here, we report on the remarkable broadening of specific heat jump near a superconducting transition tempreature (Tc) in transition-metal zirconides (TrZr2) with different mixing entropy ({Delta}Smix) at the Tr site. With increasing {Delta}Smix, the superconducting transition seen in specific heat became broader, whereas those seen in magnetization were commonly sharp. Therefore the broadening of specific heat jump would be related to the microscopic inhomogeneity of the formation of Cooper pairs behind the emergence of bulk superconductivity states.
The low-temperature specific heat of a superconductor Mo3Sb7 with T_c = 2.25 (0.05) K has been measured in magnetic fields up to 5 T. In the normal state, the electronic specific heat coefficient gamma_n, and the Debye temperature Theta_D are found t
o be 34.5(2) mJ/molK^2 and 283(5) K, respectively. The enhanced gamma_n value is interpreted due to a narrow Mo-4d band pinned at the Fermi level. The electronic specific heat in the superconducting state can be analyzed in terms a phenomenological two BCS-like gap model with the gap widths 2Delta_1/k_BT_c = 4.0 and 2Delta_2/k_BT_c = 2.5, and relative weights of the mole electronic heat coefficients gamma_1/gamma_n = 0.7 and gamma_2/gamma_n = 0.3. Some characteristic thermodynamic parameters for the studied superconductor, like the specific heat jump at T_c, DeltaC_p(T_c)/gamma_nT_c, the electron-phonon coupling constant,lambda_eph, the upper H_c2 and thermodynamic critical H_c0 fields, the penetration depth, lambda, coherence length xi, and the Ginzburg-Landau parameter kappa are evaluated. The estimated values of parameters like 2Delta/k_BT_c, DeltaC_p(T_c)/gamma_nT_c, N(E_F), and lambda_eph suggest that Mo3Sb7 belongs to intermediate-coupling regime. The electronic band structure calculations indicate that the density of states near the Fermi level is formed mainly by the Mo-4d orbitals and there is no overlapping between the Mo- 4d and Sb-sp orbitals.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
