| Project/Area Number |
09440126
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
固体物性Ⅱ(磁性・金属・低温)
|
|---|
| Research Institution | HOKKAIDO UNIVERSITY |
|---|
Principal Investigator |
ODA Migaku Hokkaido Univ., Grad. School of Sci., Asso. Pro., 大学院・理学研究科, 助教授 (70204211)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MOMONO Naoki Hokkaido Univ., Grad. School of Sci., Inst., 大学院・理学研究科, 助手 (00261280)
IDO Masayuki Hokkaido Univ., Grad. School of Sci., Pro., 大学院・理学研究科, 教授 (90111145)
|
|---|
| Project Period (FY) |
1997 – 1999
|
| Project Status |
Completed (Fiscal Year 1999)
|
| Budget Amount *help |
¥10,200,000 (Direct Cost: ¥10,200,000)
Fiscal Year 1999: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1998: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1997: ¥7,600,000 (Direct Cost: ¥7,600,000)
|
|---|
| Keywords | 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 |
|---|
| Research Abstract |
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.
|
