Competition of disorder and interchain hopping in a two-chain Hubbard model

Orignac, Edmond; Suzumura, Yoshikazu

doi:10.1007/s100510170082

Cited by 7 publications

(5 citation statements)

References 54 publications

(118 reference statements)

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“…(22a) to Eq. (22h), describe the RG flow of coupling constants within the two degenerate E ′ bands, which coincide with those derived in the two-leg-ladder model 27 . The last five equations, Eq.…”

Section: Vi2 One-loop Rgsupporting

confidence: 76%

Instability of three-band Tomonaga-Luttinger liquid: renormalization group analysis and possible application to K2Cr3As3

Miao,

Zhang,

Zhou

2016

Preprint

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Motivated by recently discovered quasi-one-dimensional superconductor K2Cr3As3 with D 3h lattice symmetry, we study one-dimensional three-orbital Hubbard model with generic electron repulsive interaction described by intra-orbital repulsion U , inter-orbital repulsion U ′ , and Hund's coupling J. As extracted from density functional theory calculation, two of the three atomic orbitals are degenerate (E ′ states) and the third one is non-degenerate (A ′ 1 ), and the system is at incommensurate filling. With the help of bosonization, the normal state is described by a threeband Tomonaga-Luttinger liquid. Possible charge density wave (CDW), spin density wave (SDW) and superconducting (SC) instabilities are analyzed by renormalization group method. The ground state depends on the ratio J/U and is sensitive to the degeneracy of E ′ bands. Spin-singlet SC state is favored at 0 < J < U/3, and spin-triplet SC state is favored in the region U/3 < J < U/2. The SDW state has the lowest energy only in the unphysical parameter region J > U/2. When the two-fold degeneracy of E ′ bands is lifted, SDW instability has the tendency to dominate over the spin-singlet SC state at 0 < J < U/3, while the order parameter of the spin-triplet SC state will be modulated by a phase factor 2∆kF x at U/3 < J < U/2. Possible experimental consequences and applications to K2Cr3As3 are discussed.

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Section: Vi2 One-loop Rgsupporting

confidence: 76%

Instability of three-band Tomonaga-Luttinger liquid: renormalization group analysis and possible application to K2Cr3As3

Miao,

Zhang,

Zhou

2016

Preprint

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“…This sign might be fixed using higher-order perturbation theory as in Ref. [61] or numerically by looking at the different lattice order parameters of the problem. In this respect, for g c > 0, we have the long-range ordering of a q = 2N k F = π/a 0 CDW: ρ π = j,α (−1) j c † j,α c j,α = 0 while for g c < 0 a spin-Peierls (bond) ordering is formed: O SP = j,α (−1) j c † j+1,α c j,α + H.c. = 0.…”

Section: Mott III Phasementioning

confidence: 99%

Competing orders in one-dimensional half-integer fermionic cold atoms: A conformal field theory approach

2008

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The physical properties of arbitrary half-integer spins F = N − 1/2 fermionic cold atoms loaded into a one-dimensional optical lattice are investigated by means of a conformal field theory approach. We show that for attractive interactions two different superfluid phases emerge for F ≥ 3/2: A BCS pairing phase, and a molecular superfluid phase which is formed from bound-states made of 2N fermions. In the low-energy approach, the competition between these instabilities and charge-density waves is described in terms of Z N parafermionic degrees of freedom. The quantum phase transition for F = 3/2, 5/2 is universal and shown to belong to the Ising and three-state Potts universality classes respectively. In contrast, for F ≥ 7/2, the transition is non-universal. For a filling of one atom per site, a Mott transition occurs and the nature of the possible Mott-insulating phases are determined. spins F = N − 1/2 fermionic cold atoms with s-wave scattering interactions loaded into a onedimensional optical lattice. The low-energy physical properties of 2F +1 = 2N -component fermions with contact interactions are known to be described by a Hubbard-like Hamiltonian [5]:where c † α,i (α = 1, ..., 2N ) is the fermion creation operator corresponding to the 2F + 1 = 2N atomic states and n i = α c † α,i c α,i is the density operator on site i. The pairing operators in Eq. (1) are defined through the Clebsch-Gordan coefficients for forming a total spin J from two spin-F fermions: P † JM,i = αβ JM |F, F ; αβ c † α,i c † β,i . The interactions are SU(2) spin-conserving and depend on U J parameters corresponding to the total spin J which takes only even integers value due to Pauli's principle: J = 0, 2, ..., 2N − 2. Even in this simple scheme the interaction pattern is still involved since there are N coupling constants in the general spin-F case. In this paper, we shall consider a two coupling-constant version of model (1) which incorporates the relevant physics of higher-spin degeneracy with respect to the formation of an exotic MS phase. To this end, it is enlightening to express this model in terms of the density n i and the BCS singlet-pairing operator for spin-F which is defined by: P † 00,i =

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Section: 14mentioning

confidence: 99%

“…24,25 At low temperatures, this leads to a rather surprising response to even a single impurity, 26 and many different possibilities in the presence of a disorder potential. [27][28][29] There has also been a lot of interest in magnetic-field induced phase transitions in the clean ladder systems at low temperature. [30][31][32][33] While these works set the scene for the present study, we will be interested in quite a different regime where we have temperature sufficiently high that we can a) neglect the gaps opened by the interaction backscattering g 1 terms; and b) consider sufficiently strong dephasing that the disorder potential may be treated peturbatively.…”

Section: Introductionmentioning

confidence: 99%

Weak localization and magnetoresistance in a two-leg ladder model

et al. 2012

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We analyze the weak localization correction to the conductivity of a spinless two-leg ladder model in the limit of strong dephasing τ φ τtr, paying particular attention to the presence of a magnetic field, which leads to an unconventional magnetoresistance behavior. We find that the magnetic field leads to three different effects: (i) negative magnetoresistance due to the regular weak localization correction (ii) effective decoupling of the two chains, leading to positive magnetoresistance and (iii) oscillations in the magnetoresistance originating from the nature of the low-energy collective excitations. All three effects can be observed depending on the parameter range, but it turns out that large magnetic fields always decouple the chains and thus lead to the curious effect of magnetic field enhanced localization.

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Competition of disorder and interchain hopping in a two-chain Hubbard model

Cited by 7 publications

References 54 publications

Instability of three-band Tomonaga-Luttinger liquid: renormalization group analysis and possible application to K2Cr3As3

Instability of three-band Tomonaga-Luttinger liquid: renormalization group analysis and possible application to K2Cr3As3

Competing orders in one-dimensional half-integer fermionic cold atoms: A conformal field theory approach

Weak localization and magnetoresistance in a two-leg ladder model

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