Particle-Hole Symmetry Breaking in the Pseudogap State of Bi2201

Journal Article · Fri Aug 19 04:00:00 EDT 2011 · Submitted to Nature Physics

OSTI ID:1022494

Hashimoto, M; He, R -H; Tanaka, K; Testaud, J P; Meevasana1, W; Moore, R G; Lu, D H; Yao, H; Yoshida, Y; Eisaki, H; Devereaux, T P; Hussain, Z; Shen, Z -X

In conventional superconductors, a gap exists in the energy absorption spectrum only below the transition temperature (T{sub c}), corresponding to the energy price to pay for breaking a Cooper pair of electrons. In high-T{sub c} cuprate superconductors above T{sub c}, an energy gap called the pseudogap exists, and is controversially attributed either to pre-formed superconducting pairs, which would exhibit particle-hole symmetry, or to competing phases which would typically break it. Scanning tunnelling microscopy (STM) studies suggest that the pseudogap stems from lattice translational symmetry breaking and is associated with a different characteristic spectrum for adding or removing electrons (particle-hole asymmetry). However, no signature of either spatial or energy symmetry breaking of the pseudogap has previously been observed by angle-resolved photoemission spectroscopy (ARPES). Here we report ARPES data from Bi2201 which reveals both particle-hole symmetry breaking and dramatic spectral broadening indicative of spatial symmetry breaking without long range order, upon crossing through T* into the pseudogap state. This symmetry breaking is found in the dominant region of the momentum space for the pseudogap, around the so-called anti-node near the Brillouin zone boundary. Our finding supports the STM conclusion that the pseudogap state is a broken-symmetry state that is distinct from homogeneous superconductivity.

• Research Organization: SLAC National Accelerator Laboratory (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 1022494
• Report Number(s): SLAC-PUB-14019
• Journal Information: Submitted to Nature Physics, Journal Name: Submitted to Nature Physics
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ASYMMETRY
Astrophysics
ASTRO
BRILLOUIN ZONES
COOPER PAIRS
CUPRATES
ELECTRONS
ENERGY ABSORPTION
ENERGY GAP
LINE BROADENING
MICROSCOPY
PHOTOEMISSION
PRICES
SPECTROSCOPY
SUPERCONDUCTIVITY
SUPERCONDUCTORS
SYMMETRY
SYMMETRY BREAKING
TRANSITION TEMPERATURE