Charge ordering and local-singlet formation in quarter-filled band charge-transfer solids and oxides of early transition metals

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

In many 1/4-filled band nonsuperconducting charge-transfer solids (CTS), such as the θ-(ET)2X and the "ladder" compounds (DT-TTF)2Au(mnt)2 a charge-ordering (CO) transition is followed by a transition to a spin-gap (SG) state. This phenomenon is of interest because (a) SG in dimensionality greater than 1 is relatively rare, and (b) similar SG transitions, preceded or accompanied by a CO transition, are also seen in 1/4-filled band oxides of early transition metals such as Ti 4O7 and α-NaV2O5. The mechanisms of the SG formations are not understood and are often controversial. We present a global perspective of the CO transitions in 1/4-filled band systems. We report calculations incorporating both electron-electron and electron-phonon interactions in 1/4-filled band (a) 1D chains (b) 2D rectangular and triangular lattices, and (c) zigzag and rectangular ladders. We show that CO in many 1/4-filled band materials involves the formation of "local dimers" or "intersite bipolarons" that are bound into a singlet state, thereby giving a SG. Our work presents a new mechanism for singlet formation in a wide variety of exotic semiconductors below the metal-semiconductor transition. We discuss the above CTS and oxides in the context of the theory, and speculate on the possible role of local dimers in the superconductivity observed in structurally related CTS and Ti- and V-oxides.

Original languageEnglish (US)
Title of host publicationJournal De Physique. IV : JP
EditorsS. Brazovskii, P. Monceau, N. Kirova
Pages63
Number of pages1
Volume131
DOIs
StatePublished - 2005
EventECRYS-2005: International Workshop on Electronic Crystals - Cargese, France
Duration: Aug 21 2005Aug 27 2005

Other

OtherECRYS-2005: International Workshop on Electronic Crystals
CountryFrance
CityCargese
Period8/21/058/27/05

Fingerprint

transition metals
charge transfer
oxides
ladders
dimers
electron phonon interactions
electrons
superconductivity
metals

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Mazumdar, S., & Clay, R. T. (2005). Charge ordering and local-singlet formation in quarter-filled band charge-transfer solids and oxides of early transition metals. In S. Brazovskii, P. Monceau, & N. Kirova (Eds.), Journal De Physique. IV : JP (Vol. 131, pp. 63) https://doi.org/10.1051/jp4:2005131013

Charge ordering and local-singlet formation in quarter-filled band charge-transfer solids and oxides of early transition metals. / Mazumdar, Sumitendra; Clay, R. T.

Journal De Physique. IV : JP. ed. / S. Brazovskii; P. Monceau; N. Kirova. Vol. 131 2005. p. 63.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Mazumdar, S & Clay, RT 2005, Charge ordering and local-singlet formation in quarter-filled band charge-transfer solids and oxides of early transition metals. in S Brazovskii, P Monceau & N Kirova (eds), Journal De Physique. IV : JP. vol. 131, pp. 63, ECRYS-2005: International Workshop on Electronic Crystals, Cargese, France, 8/21/05. https://doi.org/10.1051/jp4:2005131013
Mazumdar, Sumitendra ; Clay, R. T. / Charge ordering and local-singlet formation in quarter-filled band charge-transfer solids and oxides of early transition metals. Journal De Physique. IV : JP. editor / S. Brazovskii ; P. Monceau ; N. Kirova. Vol. 131 2005. pp. 63
@inproceedings{887866f6ee6349f0a68f59c65ffa3dd1,
title = "Charge ordering and local-singlet formation in quarter-filled band charge-transfer solids and oxides of early transition metals",
abstract = "In many 1/4-filled band nonsuperconducting charge-transfer solids (CTS), such as the θ-(ET)2X and the {"}ladder{"} compounds (DT-TTF)2Au(mnt)2 a charge-ordering (CO) transition is followed by a transition to a spin-gap (SG) state. This phenomenon is of interest because (a) SG in dimensionality greater than 1 is relatively rare, and (b) similar SG transitions, preceded or accompanied by a CO transition, are also seen in 1/4-filled band oxides of early transition metals such as Ti 4O7 and α-NaV2O5. The mechanisms of the SG formations are not understood and are often controversial. We present a global perspective of the CO transitions in 1/4-filled band systems. We report calculations incorporating both electron-electron and electron-phonon interactions in 1/4-filled band (a) 1D chains (b) 2D rectangular and triangular lattices, and (c) zigzag and rectangular ladders. We show that CO in many 1/4-filled band materials involves the formation of {"}local dimers{"} or {"}intersite bipolarons{"} that are bound into a singlet state, thereby giving a SG. Our work presents a new mechanism for singlet formation in a wide variety of exotic semiconductors below the metal-semiconductor transition. We discuss the above CTS and oxides in the context of the theory, and speculate on the possible role of local dimers in the superconductivity observed in structurally related CTS and Ti- and V-oxides.",
author = "Sumitendra Mazumdar and Clay, {R. T.}",
year = "2005",
doi = "10.1051/jp4:2005131013",
language = "English (US)",
volume = "131",
pages = "63",
editor = "S. Brazovskii and P. Monceau and N. Kirova",
booktitle = "Journal De Physique. IV : JP",

}

TY - GEN

T1 - Charge ordering and local-singlet formation in quarter-filled band charge-transfer solids and oxides of early transition metals

AU - Mazumdar, Sumitendra

AU - Clay, R. T.

PY - 2005

Y1 - 2005

N2 - In many 1/4-filled band nonsuperconducting charge-transfer solids (CTS), such as the θ-(ET)2X and the "ladder" compounds (DT-TTF)2Au(mnt)2 a charge-ordering (CO) transition is followed by a transition to a spin-gap (SG) state. This phenomenon is of interest because (a) SG in dimensionality greater than 1 is relatively rare, and (b) similar SG transitions, preceded or accompanied by a CO transition, are also seen in 1/4-filled band oxides of early transition metals such as Ti 4O7 and α-NaV2O5. The mechanisms of the SG formations are not understood and are often controversial. We present a global perspective of the CO transitions in 1/4-filled band systems. We report calculations incorporating both electron-electron and electron-phonon interactions in 1/4-filled band (a) 1D chains (b) 2D rectangular and triangular lattices, and (c) zigzag and rectangular ladders. We show that CO in many 1/4-filled band materials involves the formation of "local dimers" or "intersite bipolarons" that are bound into a singlet state, thereby giving a SG. Our work presents a new mechanism for singlet formation in a wide variety of exotic semiconductors below the metal-semiconductor transition. We discuss the above CTS and oxides in the context of the theory, and speculate on the possible role of local dimers in the superconductivity observed in structurally related CTS and Ti- and V-oxides.

AB - In many 1/4-filled band nonsuperconducting charge-transfer solids (CTS), such as the θ-(ET)2X and the "ladder" compounds (DT-TTF)2Au(mnt)2 a charge-ordering (CO) transition is followed by a transition to a spin-gap (SG) state. This phenomenon is of interest because (a) SG in dimensionality greater than 1 is relatively rare, and (b) similar SG transitions, preceded or accompanied by a CO transition, are also seen in 1/4-filled band oxides of early transition metals such as Ti 4O7 and α-NaV2O5. The mechanisms of the SG formations are not understood and are often controversial. We present a global perspective of the CO transitions in 1/4-filled band systems. We report calculations incorporating both electron-electron and electron-phonon interactions in 1/4-filled band (a) 1D chains (b) 2D rectangular and triangular lattices, and (c) zigzag and rectangular ladders. We show that CO in many 1/4-filled band materials involves the formation of "local dimers" or "intersite bipolarons" that are bound into a singlet state, thereby giving a SG. Our work presents a new mechanism for singlet formation in a wide variety of exotic semiconductors below the metal-semiconductor transition. We discuss the above CTS and oxides in the context of the theory, and speculate on the possible role of local dimers in the superconductivity observed in structurally related CTS and Ti- and V-oxides.

UR - http://www.scopus.com/inward/record.url?scp=33645084016&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33645084016&partnerID=8YFLogxK

U2 - 10.1051/jp4:2005131013

DO - 10.1051/jp4:2005131013

M3 - Conference contribution

AN - SCOPUS:33645084016

VL - 131

SP - 63

BT - Journal De Physique. IV : JP

A2 - Brazovskii, S.

A2 - Monceau, P.

A2 - Kirova, N.

ER -