Simple Model for T<sub><i>c</i></sub> and Pairing Symmetry Changes in Sr<sub>2</sub>RuO<sub>4</sub> Under (100) Uniaxial Strain
Uniaxial strain in the (100) direction has the effect of increasing the superconducting <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi mathvariant="normal">T</mi><mi>c</...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-11-01
|
| Series: | Condensed Matter |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2410-3896/9/4/44 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Uniaxial strain in the (100) direction has the effect of increasing the superconducting <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi mathvariant="normal">T</mi><mi>c</mi></msub></semantics></math></inline-formula> in Sr<sub>2</sub>RuO<sub>4</sub> from <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>1.5</mn></mrow></semantics></math></inline-formula> K to over 3 K. The enhanced <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>T</mi><mi>c</mi></msub></semantics></math></inline-formula> corresponds to a Lifshitz transition in the Fermi surface topology of this unconventional superconductor. We model this using a simple two-dimensional one-band model for the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula> sheet of the Fermi surface. This reproduces the experimental <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>T</mi><mi>c</mi></msub></semantics></math></inline-formula> results well if we assume a <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>d</mi><mrow><msup><mi>x</mi><mn>2</mn></msup><mo>−</mo><msup><mi>y</mi><mn>2</mn></msup></mrow></msub></semantics></math></inline-formula> singlet pairing state. On the other hand, the triplet state <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>p</mi><mi>x</mi></msub><mo>+</mo><mi>i</mi><msub><mi>p</mi><mi>y</mi></msub></mrow></semantics></math></inline-formula> does not show any distinct peaks in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi mathvariant="normal">T</mi><mi>c</mi></msub></semantics></math></inline-formula> associated with the Lifshitz transition. A mixed symmetry state pairing of the form <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>d</mi><mo>+</mo><mi>i</mi><mi>g</mi></mrow></semantics></math></inline-formula> can both describe the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>T</mi><mi>c</mi></msub></semantics></math></inline-formula> changes and show a distinct transition temperature for time-reversal symmetry breaking (TRSB). |
|---|---|
| ISSN: | 2410-3896 |