AbstractIn order to understand the superconducting gap nature of a $$\hbox {2H-Pd}_{0.08} \hbox {TaSe}_2$$
2H-Pd
0.08
TaSe
2
single crystal with $$T_{c} = 3.13 \text { K}$$
T
c
=
3.13
K
, in-plane thermal conductivity $$\kappa $$
κ
, in-plane London penetration depth $$\lambda _{\text {L}}$$
λ
L
, and the upper critical fields $$H_{c2}$$
H
c
2
have been investigated. At zero magnetic field, it is found that no residual linear term $$\kappa _{0}/T$$
κ
0
/
T
exists and $$\lambda _{\text {L}}$$
λ
L
follows a power-law $$T^n$$
T
n
(T: temperature) with n = 2.66 at $$T \le \frac{1}{3}T_c$$
T
≤
1
3
T
c
, supporting nodeless superconductivity. Moreover, the magnetic-field dependence of $$\kappa _{0}$$
κ
0
/T clearly shows a shoulder-like feature at a low field region. The temperature dependent $$H_{c2}$$
H
c
2
curves for both in-plane and out-of-plane field directions exhibit clear upward curvatures near $$T_c$$
T
c
, consistent with the shape predicted by the two-band theory and the anisotropy ratio between the $$H_{c2}$$
H
c
2
(T) curves exhibits strong temperature-dependence. All these results coherently suggest that $$\hbox {2H-Pd}_{0.08} \hbox {TaSe}_2$$
2H-Pd
0.08
TaSe
2
is a nodeless, multiband superconductor.
SPONTANEOUS SHRINKING OF THE SECOND TYPE OF DUMBBELL DOMAINS SUBJECTED TO BOTH STATIC BIAS FIELD AND IN-PLANE FIELD