Direct Observation of Fermi Pocket in High Temperature Cuprate Superconductors Export

@article{citeulike:4869495, abstract = {In ordinary superconductors the energy gap caused by Cooper pairing closes above the superconducting transition temperature(Tc). The most enigmatic property of the copper-oxide (cuprate) high temperature superconductor is the so-called "pseudogap" phenomenon"-above Tc an energy gap remains. Moreover in this unusual normal state, the pseudogap state, there are parts of the Fermi surface that remain gapless.In the past twenty years, angle-resolved photoemission (ARPES) data suggest that the gapless portion of the Fermi surface forms open ended arcs, rather than a closed loops, as an ordinary equal energy contour should be. The existence of the Fermi arcs has puzzled the physics community and triggered enormous research efforts. Here, by performing ultra-high resolution ARPES measurements on high quality Bi2(Sr2-xLax)CuO6+d(La-Bi2201) samples, we report the first direct evidence of Fermi surface topology that is distinct from the Fermi arc picture. We find that the ungapped portion of Fermi surface forms closed loops, i.e., the Fermi pockets. In addition, our finding suggests that the carriers residing on this Fermi pocket should be holes rather than electrons, and the Fermi pocket exhibits unusual doping dependence. Together with the recent quantum oscillation experiments done under high magnetic field, our observation of Fermi pocket in zero field should shed new light on the mysterious pseudogap state of cuprate high temperature superconductors.}, archivePrefix = {arXiv}, author = {Meng, Jianqiao and Liu, Guodong and Zhang, Wentao and Zhao, Lin and Liu, Haiyun and Jia, Xiaowen and Mu, Daixiang and Liu, Shanyu and Dong, Xiaoli and Lu, Wei and Wang, Guiling and Zhou, Yong and Zhu, Yong and Wang, Xiaoyang and Xu, Zuyan and Chen, Chuangtian and Zhou, X. J.}, citeulike-article-id = {4869495}, citeulike-linkout-0 = {http://arxiv.org/abs/0906.2682}, citeulike-linkout-1 = {http://arxiv.org/pdf/0906.2682}, day = {15}, eprint = {0906.2682}, keywords = {cuprates}, month = {Jun}, posted-at = {2009-06-16 20:09:17}, priority = {2}, title = {Direct Observation of Fermi Pocket in High Temperature Cuprate Superconductors}, url = {http://arxiv.org/abs/0906.2682}, year = {2009} }

TY - JOUR ID - citeulike:4869495 L3 - citeulike-article-id:4869495 N2 - In ordinary superconductors the energy gap caused by Cooper pairing closes above the superconducting transition temperature(Tc). The most enigmatic property of the copper-oxide (cuprate) high temperature superconductor is the so-called "pseudogap" phenomenon"-above Tc an energy gap remains. Moreover in this unusual normal state, the pseudogap state, there are parts of the Fermi surface that remain gapless.In the past twenty years, angle-resolved photoemission (ARPES) data suggest that the gapless portion of the Fermi surface forms open ended arcs, rather than a closed loops, as an ordinary equal energy contour should be. The existence of the Fermi arcs has puzzled the physics community and triggered enormous research efforts. Here, by performing ultra-high resolution ARPES measurements on high quality Bi2(Sr2-xLax)CuO6+d(La-Bi2201) samples, we report the first direct evidence of Fermi surface topology that is distinct from the Fermi arc picture. We find that the ungapped portion of Fermi surface forms closed loops, i.e., the Fermi pockets. In addition, our finding suggests that the carriers residing on this Fermi pocket should be holes rather than electrons, and the Fermi pocket exhibits unusual doping dependence. Together with the recent quantum oscillation experiments done under high magnetic field, our observation of Fermi pocket in zero field should shed new light on the mysterious pseudogap state of cuprate high temperature superconductors. TI - Direct Observation of Fermi Pocket in High Temperature Cuprate Superconductors KW - cuprates AU - Meng, Jianqiao AU - Liu, Guodong AU - Zhang, Wentao AU - Zhao, Lin AU - Liu, Haiyun AU - Jia, Xiaowen AU - Mu, Daixiang AU - Liu, Shanyu AU - Dong, Xiaoli AU - Lu, Wei AU - Wang, Guiling AU - Zhou, Yong AU - Zhu, Yong AU - Wang, Xiaoyang AU - Xu, Zuyan AU - Chen, Chuangtian AU - Zhou, XJ PY - 2009/Jun/15/ UR - http://arxiv.org/abs/0906.2682 ER -