Scanning tunneling microscopy studies on Zhang-Rice singlet state and high-TィイD2cィエD2 superconductivity

张莱斯单线态和高T2D2超导的扫描隧道显微镜研究

• 批准号: 09440126
• 负责人: ODA Migaku
• 金额: $ 6.53万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09440126/
• 关键词: high-TィイD2cィエD2 superconductor; superconducting gap; pseudogap; superconducting mechanism; 走査トンネル分光; 超伝導臨界揺らぎ; 銅酸化物超伝導体; 走査型トンネル顕微鏡; 超伝導転移温度; 一重項対; STM; STS; 銅酸化物高温超伝導体

In the present study, we have been obtained the following results.1) In Bi2212 and La214, the low temperature (T<<TィイD2cィエD2) energy gap 2ΔィイD2oィエD2 increases with the lowering of the hole doping level p and scales with pseudogap temperature TィイD1*ィエD1 over a wide p range; TィイD1*ィエD1 is comparable to the mean-fieid TィイD2cィエD2(TィイD2coィエD2). This result provides a strong evidence for the pseudogap being related to the high-TィイD2cィエD2 superconductivity.2) On the basis of the dependences of electronic specific heat and magnetic susceptibility, it was found that the superconducting critical fluctuation develops markedly below a certain temperature TィイD2sf' ィエD2, 〜20% higher than TィイD2cィエD2 and much lower than TィイD1*ィエD1〜TィイD2coィエD2. This suggests that the motion of singlet pairs, whose formation will give rise to the pseudogap below 〜TィイD1*ィエD1, tends to become coherent below 〜TィイD2sfィエD2 to establish long-range phase coherence at TィイD2cィエD2.3) In Bi2212 and La214, TィイD2cィエD2 nearly scales with pΔィイD2oィエD2 ; kィイD2BィエD2TィイD2cィエD2〜pΔィイD2oィエD2. This indicates that the energy scale in determining TィイD2cィエD2, is of the order of pΔィイD2oィエD2, which is a striking feature of high-TィイD2cィエD2 cuprates, differing from that expected in conventional superconductors.In the present study, a scenario for the superconducting transition mechanism has also been proposed on the basis of the results mentioned above.

在目前的研究中，我们得到了以下结果。1)在Bi2212和La214,低温(T < < TィイD2cィエD2)能隙2ΔィイD2oィエD2洞掺杂水平的增加而降低p和尺度与赝能隙温度TィイD1 *ィエD1 / p范围宽;T ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` `这一结果有力地证明了赝隙与高t_(_(_) _(_) _() _() _() _() _（）超导性有关。2)的基础上,电子比热的依赖性和磁化率,发现超导临界波动发展明显低于一定温度TィイD2sf”ィエD2, ~ 20%高于TィイD2cィエD2和远低于TィイD1 *ィエD1 ~ TィイD2coィエD2。这表明，单重态对的运动在~ T γ γ γ D1* γ γ γ γ D1以下产生赝隙，在~ T γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ。k γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ γ。这表明，在确定T φ φ D2c c φ φ D2时，能量标度为pΔ φ φ d20 φ φ D2数量级，这是高T φ φ D2c c φ φ D2铜酸盐的显著特征，与传统超导体的期望不同。本研究在上述结果的基础上，提出了超导跃迁机制的设想。

项目成果

N. Momono: "Pseudogap behavior in the electronic specific heat of La_<2-x>Sr_xCuO_4"J. Low Temp. Phys.. 117. 353-357 (1999)

N. Momono：“La_<2-x>Sr_xCuO_4 电子比热中的赝能隙行为”J。

M.Oda: "Superconducting gap in tunneling spectra and pcencls gap behavior on high-Tc cuprates"Int.J.of Modern Phys.B. 13. 3605-3609 (1999)

M.Oda：“隧道光谱中的超导能隙和高温铜酸盐上的 pcencls 能隙行为”Int.J.of Modern Phys.B。

C.Manabe: "Atomicimages and tunneling spectra on Bi_2Sr_2 CaCu_2O_<8+>S cleaved Surface by STM"J.Phys.Soc.Jpn.. 66. 1776-1784 (1997)

C.Manabe：“通过 STM 在 Bi_2Sr_2 CaCu_2O_<8 >S 解理表面上获得原子图像和隧道光谱”J.Phys.Soc.Jpn.. 66. 1776-1784 (1997)

T.Nakano: "Conelation between the doping dependences of superconducting gap magnitude 2Δ_0 and pseudogap temperatare T^* in luzlo-Tc auprates"J.Phys.Soc.Jpn.. 67. 2622-2625 (1998)

T.Nakano：“luzlo-Tc auprates 中超导能隙大小 2Δ_0 与赝能隙温度 T^* 的掺杂依赖性之间的关联”J.Phys.Soc.Jpn.. 67. 2622-2625 (1998)

小田研: "高温超電導体の擬ギャップと超伝導"物理学会誌. 53. 192-196 (1998)

小田实验室：“高温超导体中的赝间隙和超导性”日本物理学会杂志 53. 192-196 (1998)。