Details

Autor(en) / Beteiligte

• Veenstra, C N
• Zhu, Z-H
• Raichle, M
• Ludbrook, B M
• Nicolaou, A
• Slomski, B
• Landolt, G
• Kittaka, S
• Maeno, Y
• Dil, J H
• Elfimov, I S
• Haverkort, M W
• Damascelli, A

Titel

Spin-orbital entanglement and the breakdown of singlets and triplets in Sr2RuO4 revealed by spin- and angle-resolved photoemission spectroscopy

Ist Teil von

• Physical review letters, 2014-03, Vol.112 (12), p.127002-127002

Ort / Verlag

United States

Erscheinungsjahr

2014

Link zum Volltext

Quelle

American Physical Society

Beschreibungen/Notizen

• Spin-orbit coupling has been conjectured to play a key role in the low-energy electronic structure of Sr2RuO4. By using circularly polarized light combined with spin- and angle-resolved photoemission spectroscopy, we directly measure the value of the effective spin-orbit coupling to be 130±30  meV. This is even larger than theoretically predicted and comparable to the energy splitting of the dxy and dxz,yz orbitals around the Fermi surface, resulting in a strongly momentum-dependent entanglement of spin and orbital character in the electronic wavefunction. As demonstrated by the spin expectation value ⟨sk⃗·s-k⃗⟩ calculated for a pair of electrons with zero total momentum, the classification of the Cooper pairs in terms of pure singlets or triplets fundamentally breaks down, necessitating a description of the unconventional superconducting state of Sr2RuO4 in terms of these newly found spin-orbital entangled eigenstates.