| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Mathieu, Roland, et al.
(author)
-
Bandwidth-disorder phase diagram of half-doped layered manganites
- 2006
-
In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 74:2
-
Journal article (peer-reviewed)abstract
- Phase diagrams in the plane of rA (the average ionic radius, related to the one-electron bandwidth W) and σ2 (the ionic radius variance, measuring the quenched disorder), or bandwidth-disorder phase diagrams, have been established for perovskite manganites, with a three-dimensional (3D) Mn-O network. Here we establish the intrinsic bandwidth-disorder phase diagram of half-doped layered manganites with a two-dimensional (2D) Mn-O network, examining in detail the parent state of the colossal magnetoresistance phenomenon in crystals without ferromagnetic instability. The consequences of the reduced dimensionality, from 3D to 2D, for the order-disorder phenomena in the charge-orbital sectors are also highlighted.
|
|
| 6. |
|
|
| 7. |
- Cheng, Y. Y., et al.
(author)
-
Nucleon-pair states of even-even Sn isotopes based on realistic effective interactions
- 2016
-
In: PHYSICAL REVIEW C. - : American Physical Society. - 2469-9985. ; 94:2
-
Journal article (peer-reviewed)abstract
- In this paper we study yrast states of Sn-128,Sn-126,Sn-124 and Sn-104,Sn-106,Sn-108 by using the monopole-optimized realistic interactions in terms of both the shell model (SM) and the nucleon-pair approximation (NPA). For yrast states of Sn-128,Sn-126 and Sn-104,Sn-106, we calculate the overlaps between the wave functions obtained in the full SM space and those obtained in the truncated NPA space, and find that most of these overlaps are very close to 1. Very interestingly, for most of these states with positive parity and even spin or with negative parity and odd spin, the SM wave function is found to be well represented by one nucleon-pair basis state, viz., a simple picture of "nucleon-pair states" (nucleon-pair configuration without mixings) emerges. In Sn-128,Sn-126, the positive-parity (or negative-parity) yrast states with spin J > 10 (or J > 7) are found to be well described by breaking one or two S pairs in the 10(1)(+) (or 7(1)(-)) state, i.e., the yrast state of seniority-two, spin-maximum, and positive-parity (or negative-parity), into non-S pair(s). Similar regularity is also pointed out for Sn-104,Sn-106. The evolution of E2 transition rates between low-lying states in Sn-128,Sn-126,Sn-124 is discussed in terms of the seniority scheme.
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Mathieu, Roland, et al.
(author)
-
Coexistence of long-ranged charge and orbital order and spin-glass state in single-layered manganites with weak quenched disorder
- 2007
-
In: Europhysics letters. - : IOP Publishing. - 0295-5075 .- 1286-4854. ; 80:3, s. 37001-
-
Journal article (peer-reviewed)abstract
- The relationship between orbital and spin degrees of freedom in the single crystals of the hole-doped Pr1-xCa1+xMnO4, 0.3 <= x <= 0.7 has been investigated by means of ac-magnetometry and charge transport. We show that in an intermediate underdoped region, with 0.35 <= x < 0.5, the "orbital-master spin-slave" relationship commonly observed in half-doped manganites does not take place. The long-ranged charge-orbital order is not accompanied by an antiferromagnetic transition at low temperatures, but by a frustrated short-ranged magnetic state bringing forth a spin-glass phase. We discuss in detail the nature and origin of this true spin-glass state, which, as in the half-doped manganites with large quenched disorder, is not related to the macroscopic phase separation observed in crystals with minor defects or impurities.
|
|
