Subir Sachdev (Yale) Philipp Werner (ETH) Matthias Troyer (ETH) Universal conductance of nanowires...
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![Page 1: Subir Sachdev (Yale) Philipp Werner (ETH) Matthias Troyer (ETH) Universal conductance of nanowires near the superconductor-metal quantum transition cond-mat/0402431.](https://reader035.fdocuments.net/reader035/viewer/2022062804/56649d495503460f94a25189/html5/thumbnails/1.jpg)
Subir Sachdev (Yale)Philipp Werner (ETH)Matthias Troyer (ETH)
Universal conductance of nanowires near the superconductor-metal quantum transition
cond-mat/0402431
Talk online: Sachdev
![Page 2: Subir Sachdev (Yale) Philipp Werner (ETH) Matthias Troyer (ETH) Universal conductance of nanowires near the superconductor-metal quantum transition cond-mat/0402431.](https://reader035.fdocuments.net/reader035/viewer/2022062804/56649d495503460f94a25189/html5/thumbnails/2.jpg)
T=0 Superconductor-metal transition
Attractive BCS interaction
R
Repulsive BCS interaction
RRc
Metal Superconductor
M.V. Feigel'man and A.I. Larkin, Chem. Phys. 235, 107 (1998)B. Spivak, A. Zyuzin, and M. Hruska, Phys. Rev. B 64, 132502 (2001).
![Page 3: Subir Sachdev (Yale) Philipp Werner (ETH) Matthias Troyer (ETH) Universal conductance of nanowires near the superconductor-metal quantum transition cond-mat/0402431.](https://reader035.fdocuments.net/reader035/viewer/2022062804/56649d495503460f94a25189/html5/thumbnails/3.jpg)
T=0 Superconductor-metal transition
R
i
![Page 4: Subir Sachdev (Yale) Philipp Werner (ETH) Matthias Troyer (ETH) Universal conductance of nanowires near the superconductor-metal quantum transition cond-mat/0402431.](https://reader035.fdocuments.net/reader035/viewer/2022062804/56649d495503460f94a25189/html5/thumbnails/4.jpg)
Continuum theory for quantum critical point
![Page 5: Subir Sachdev (Yale) Philipp Werner (ETH) Matthias Troyer (ETH) Universal conductance of nanowires near the superconductor-metal quantum transition cond-mat/0402431.](https://reader035.fdocuments.net/reader035/viewer/2022062804/56649d495503460f94a25189/html5/thumbnails/5.jpg)
Consequences of hyperscaling
R
SuperconductorNormal
Rc
Sharp transition at T=0
T
No transition for T>0 in d=1
![Page 6: Subir Sachdev (Yale) Philipp Werner (ETH) Matthias Troyer (ETH) Universal conductance of nanowires near the superconductor-metal quantum transition cond-mat/0402431.](https://reader035.fdocuments.net/reader035/viewer/2022062804/56649d495503460f94a25189/html5/thumbnails/6.jpg)
Consequences of hyperscaling
R
SuperconductorNormal
Rc
Sharp transition at T=0
T
Quantum CriticalRegion
No transition for T>0 in d=1
![Page 7: Subir Sachdev (Yale) Philipp Werner (ETH) Matthias Troyer (ETH) Universal conductance of nanowires near the superconductor-metal quantum transition cond-mat/0402431.](https://reader035.fdocuments.net/reader035/viewer/2022062804/56649d495503460f94a25189/html5/thumbnails/7.jpg)
Consequences of hyperscaling
Quantum CriticalRegion
![Page 8: Subir Sachdev (Yale) Philipp Werner (ETH) Matthias Troyer (ETH) Universal conductance of nanowires near the superconductor-metal quantum transition cond-mat/0402431.](https://reader035.fdocuments.net/reader035/viewer/2022062804/56649d495503460f94a25189/html5/thumbnails/8.jpg)
Consequences of hyperscaling
Quantum CriticalRegion
![Page 9: Subir Sachdev (Yale) Philipp Werner (ETH) Matthias Troyer (ETH) Universal conductance of nanowires near the superconductor-metal quantum transition cond-mat/0402431.](https://reader035.fdocuments.net/reader035/viewer/2022062804/56649d495503460f94a25189/html5/thumbnails/9.jpg)
Effect of the leads
![Page 10: Subir Sachdev (Yale) Philipp Werner (ETH) Matthias Troyer (ETH) Universal conductance of nanowires near the superconductor-metal quantum transition cond-mat/0402431.](https://reader035.fdocuments.net/reader035/viewer/2022062804/56649d495503460f94a25189/html5/thumbnails/10.jpg)
Large n computation of conductance
![Page 11: Subir Sachdev (Yale) Philipp Werner (ETH) Matthias Troyer (ETH) Universal conductance of nanowires near the superconductor-metal quantum transition cond-mat/0402431.](https://reader035.fdocuments.net/reader035/viewer/2022062804/56649d495503460f94a25189/html5/thumbnails/11.jpg)
Quantum Monte Carlo and large n computation of d.c. conductance
![Page 12: Subir Sachdev (Yale) Philipp Werner (ETH) Matthias Troyer (ETH) Universal conductance of nanowires near the superconductor-metal quantum transition cond-mat/0402431.](https://reader035.fdocuments.net/reader035/viewer/2022062804/56649d495503460f94a25189/html5/thumbnails/12.jpg)
Conclusions
• Universal transport in wires near the superconductor-metal transition
• Theory includes contributions from thermal and quantum phase slips ---- reduces to the classical LAMH theory at high temperatures
• Sensitivity to leads should be a generic feature of the ``coherent’’ transport regime of quantum critical points.
Conclusions
• Universal transport in wires near the superconductor-metal transition
• Theory includes contributions from thermal and quantum phase slips ---- reduces to the classical LAMH theory at high temperatures
• Sensitivity to leads should be a generic feature of the ``coherent’’ transport regime of quantum critical points.