Pressure dependence of upper critical field in Ising superconductor 4Hb-TaS<sub>2</sub>
Oral-Virtual
Abstract
The naturally occurring van der Waals heterostructure 4Hb-TaS2, comprising
alternating insulating and metallic layers, exhibits Ising superconductivity characterized
by an upper critical field that significantly exceeds the Pauli paramagnetic limit.
Furthermore, 4Hb-TaS2 has been identified as a promising platform for chiral
superconductivity [1], which holds potential for topologically protected quantum
computation. At high temperatures, this compound undergoes charge-density-wave
(CDW) transitions, and the interplay between the CDW and superconducting states
remains elusive.
To explore this relationship, we applied hydrostatic pressure to single crystals of
4Hb-TaS2. The application of pressure leads to a systematic suppression of the CDW
transition, accompanied by an enhancement of the superconducting critical
temperature Tc. Intriguingly, despite the increase in TC, the upper critical field
decreases with pressure. Moreover, the temperature dependence of the upper critical
field evolves from an almost linear behavior at low pressure to a nonlinear profile at
high pressure.
These findings indicate a substantial modification of the pairing mechanism under
pressure. Our results demonstrate that pressure serves as an effective tuning parameter
for manipulating the superconducting ground state in this naturally structured
heterostructure. The implications for the relationship between Ising superconductivity
and CDW order will be further discussed.
[1] A. Ribak et al., Sci. Adv. 6, eaax9480(2020)
alternating insulating and metallic layers, exhibits Ising superconductivity characterized
by an upper critical field that significantly exceeds the Pauli paramagnetic limit.
Furthermore, 4Hb-TaS2 has been identified as a promising platform for chiral
superconductivity [1], which holds potential for topologically protected quantum
computation. At high temperatures, this compound undergoes charge-density-wave
(CDW) transitions, and the interplay between the CDW and superconducting states
remains elusive.
To explore this relationship, we applied hydrostatic pressure to single crystals of
4Hb-TaS2. The application of pressure leads to a systematic suppression of the CDW
transition, accompanied by an enhancement of the superconducting critical
temperature Tc. Intriguingly, despite the increase in TC, the upper critical field
decreases with pressure. Moreover, the temperature dependence of the upper critical
field evolves from an almost linear behavior at low pressure to a nonlinear profile at
high pressure.
These findings indicate a substantial modification of the pairing mechanism under
pressure. Our results demonstrate that pressure serves as an effective tuning parameter
for manipulating the superconducting ground state in this naturally structured
heterostructure. The implications for the relationship between Ising superconductivity
and CDW order will be further discussed.
[1] A. Ribak et al., Sci. Adv. 6, eaax9480(2020)
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Presenters
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Qixiang Zhang
- Department of Physics, Tohoku University