Large Violation of the Wiedemann-Franz Law in Luttinger Liquids

Garg, Arti; Rasch, David; Shimshoni, Efrat; Rosch, Achim

doi:10.1103/physrevlett.103.096402

Cited by 60 publications

(48 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In non-interacting systems, it has been shown theoretically that the WF law is robust to impurity scattering of arbitrary strength up to the Anderson transition1234. In strongly correlated electron systems, however, the opening of a Mott gap can lead to a strong reduction of the electrical conductivity whereas the transport of heat, through spin fluctuations, can remain high10. Localization corrections associated with electron–electron interactions are also believed to induce corrections to κ e that do not scale with the WF ratio, leading to an enhancement in L / L 0 (ref.…”

Section: Discussionmentioning

confidence: 99%

“…In systems that are strictly one-dimensional (1D), even weak interactions destroy the single particle FL picture in favour of an exotic Tomonaga–Luttinger liquid (TLL) state in which the fundamental excitations are independent collective modes of spin and charge, referred to, respectively, as spinons and holons. As heat is transported by entropy (spin and charge) and electric current by charge alone, spin–charge separation is a viable mechanism for the violation of the WF law9101112. Physically, repulsive interactions in a disordered 1D chain can inhibit the propagation of holons relative to that of spinons, leading to a strongly renormalized Lorenz number9.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Gross violation of the Wiedemann–Franz law in a quasi-one-dimensional conductor

et al. 2011

View full text Add to dashboard Cite

When charge carriers are spatially confined to one dimension, conventional Fermi-liquid theory breaks down. In such Tomonaga–Luttinger liquids, quasiparticles are replaced by distinct collective excitations of spin and charge that propagate independently with different velocities. Although evidence for spin–charge separation exists, no bulk low-energy probe has yet been able to distinguish successfully between Tomonaga–Luttinger and Fermi-liquid physics. Here we show experimentally that the ratio of the thermal and electrical Hall conductivities in the metallic phase of quasi-one-dimensional Li0.9Mo6O17 diverges with decreasing temperature, reaching a value five orders of magnitude larger than that found in conventional metals. Both the temperature dependence and magnitude of this ratio are consistent with Tomonaga–Luttinger liquid theory. Such a dramatic manifestation of spin–charge separation in a bulk three-dimensional solid offers a unique opportunity to explore how the fermionic quasiparticle picture recovers, and over what time scale, when coupling to a second or third dimension is restored.

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Gross violation of the Wiedemann–Franz law in a quasi-one-dimensional conductor

et al. 2011

View full text Add to dashboard Cite

show abstract

“…4, for which the effective Lorenz ratio is found to be several times larger than L 0 and to diverge with decreasing temperature12. It should be stressed here that according to theory11, the Lorenz ratio in a TLL is highly sensitive to both d , the deviation from commensurate filling and to D , the ratio of the elastic to el-el Umklapp scattering rates. However, as noted in Fig.…”

Section: Discussionmentioning

confidence: 72%

“…For certain classes of non-FL metals, the WF law is also obeyed at low T , provided some or all of the fermionic carriers remain long-lived9. In a TLL however, the Lorenz ratio is predicted to be enhanced10, by orders of magnitude under certain commensurate conditions11, due to the idea that both elastic and inelastic scattering processes affect the flow of charge (carried by holons) more profoundly than the flow of entropy (carried by spinons). Recently, a marked enhancement of the Lorenz ratio was observed in the q1D purple bronze Li 0.9 Mo 6 O 17 12, that appeared to diverge with decreasing temperature, consistent with expectations for a TLL with repulsive interactions10.…”

mentioning

confidence: 99%

The Wiedemann-Franz law in the putative one-dimensional metallic phase of PrBa2Cu4O8

Bangura

Wakeham

et al. 2013

Sci Rep

View full text Add to dashboard Cite

The nature of the electronic state of a metal depends strongly on its dimensionality. In a system of isolated conducting chains, the Fermi-liquid (quasiparticle) description appropriate for higher dimensions is replaced by the so-called Tomonaga-Luttinger liquid picture characterized by collective excitations of spin and charge. Temperature is often regarded as a viable tuning parameter between states of different dimensionality, but what happens once thermal broadening becomes comparable to the interchain hopping energy remains an unresolved issue, one that is central to many organic and inorganic conductors. Here we use the ratio of the thermal to electrical conductivities to probe the nature of the electronic state in PrBa 2 Cu 4 O 8 as a function of temperature. We find that despite the interchain transport becoming non-metallic, the charge carriers within the CuO chains appear to retain their quasiparticle nature. This implies that temperature alone cannot induce a crossover from Fermi-liquid to Tomonaga-Luttinger-liquid behaviour in quasi-one-dimensional metals. U nderstanding how the electronic state evolves in quasi-one-dimensional (q1D) metals as coupling between individual chains is strengthened or weakened, and determining the energy scale for the Fermi-liquid to Tomonaga-Luttinger liquid (FL-TLL) crossover, remain profound theoretical problems that are relevant to a host of organic and inorganic q1D conductors 1 . Temperature T is often regarded as a viable tuning parameter between states of different dimensionality in q1D metals. For k B T , 2t H , the interchain hopping integral, charge hops coherently in all three dimensions, albeit with anisotropic velocities. Once thermal broadening is comparable to the warping of the Fermi sheets however, hopping between chains is predicted to become incoherent, leading to a putative 3D-1D dimensional crossover 2 and contrasting behaviour in the intra-and inter-chain resistivities at high T. As a result, signatures of TLL physics are expected to emerge with increasing temperature 3 . In an alternative picture, it is argued that interchain coherence in a q1D FL is robust provided the intrachain scattering rate C , e F , the Fermi energy 4 . Accordingly, there is no dimensional crossover with increasing T, and by inference, no FL-TLL crossover at elevated temperatures -the crossover to non-metallic behaviour in the interchain resistivity being simply due to the emergence of a second, incoherent hopping process which shorts out the small, but nonetheless metallic component 4 . In order to address this outstanding issue experimentally, it is necessary to identify both a material whose anisotropic resistivity exhibits behaviour consistent with predictions for a thermally-induced dimensional crossover and a physical property that shows marked differences in the putative TLL and FL regimes. According to both theory and experiment, the Wiedemann-Franz (WF) law is a viable litmus test of TLL physics in the bulk. The WF law states that the ratio of the thermal k to the e...

show abstract

“…It is well accepted that nanoscale materials may provide an opening for the thermoelectricity in meeting the challenge of being a sustainable energy source5. Huge deviation from the Wiedemann-Franz law67 in the nanostructure materials5 makes new opportunities for investigating novel thermoelectric devices with high efficiency89. Specially, spin caloritronics (spin Seebeck effect) was observed by Uchida et al1011.…”

mentioning

confidence: 99%

Ultrahigh spin thermopower and pure spin current in a single-molecule magnet

Luo

Liu

Lü

et al. 2014

Sci Rep

View full text Add to dashboard Cite

Using the non-equilibrium Green's function (NEGF) formalism within the sequential regime, we studied ultrahigh spin thermopower and pure spin current in single-molecule magnet(SMM), which is attached to nonmagnetic metal wires with spin bias and angle (θ) between the easy axis of SMM and the spin orientation in the electrodes. A pure spin current can be generated by tuning the gate voltage and temperature difference with finite spin bias and the arbitrary angle except of . In the linear regime, large thermopower can be obtained by modifying Vg and the angles (θ). These results are useful in fabricating and advantaging SMM devices based on spin caloritronics.

show abstract

Large Violation of the Wiedemann-Franz Law in Luttinger Liquids

Cited by 60 publications

References 19 publications

Gross violation of the Wiedemann–Franz law in a quasi-one-dimensional conductor

Gross violation of the Wiedemann–Franz law in a quasi-one-dimensional conductor

The Wiedemann-Franz law in the putative one-dimensional metallic phase of PrBa2Cu4O8

Ultrahigh spin thermopower and pure spin current in a single-molecule magnet

Contact Info

Product

Resources

About