Mass transport through dislocation network in solid 
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Shin, Jaeho; Chan, Moses H. W.

doi:10.1103/physrevb.99.140502

Cited by 19 publications

(22 citation statements)

References 28 publications

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“…Networks of metallic domain walls have previously been observed in Cu-intercalated TiSe 2 41 , and also in other contexts: integer quantum Hall systems 42 , magnetically ordered systems 43 , nearly commensurate charge density wave systems 44 , and also recently in moiré systems [45][46][47][48] with periodic networks determined by the moiré pattern. Remarkably, power laws have also been observed in the mass transport through a network of dislocations in solid 4 He generated by a pressure difference 49 , suggesting a more ubiquitous occurrence of the network of narrow channel transport. The mechanism for the generation of networks is system-specific-disorder, quench, dislocation, etc.…”

Section: Emergent Network Of Narrow Transport Channelsmentioning

confidence: 95%

Metal-to-insulator transition in Pt-doped TiSe2 driven by emergent network of narrow transport channels

et al. 2021

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Metal-to-insulator transitions (MIT) can be driven by a number of different mechanisms, each resulting in a different type of insulator—Change in chemical potential can induce a transition from a metal to a band insulator; strong correlations can drive a metal into a Mott insulator with an energy gap; an Anderson transition, on the other hand, due to disorder leads to a localized insulator without a gap in the spectrum. Here, we report the discovery of an alternative route for MIT driven by the creation of a network of narrow channels. Transport data on Pt substituted for Ti in 1T-TiSe2 shows a dramatic increase of resistivity by five orders of magnitude for few % of Pt substitution, with a power-law dependence of the temperature-dependent resistivity ρ(T). Our scanning tunneling microscopy data show that Pt induces an irregular network of nanometer-thick domain walls (DWs) of charge density wave (CDW) order, which pull charge carriers out of the bulk and into the DWs. While the CDW domains are gapped, the charges confined to the narrow DWs interact strongly, with pseudogap-like suppression in the local density of states, even when they were weakly interacting in the bulk, and scatter at the DW network interconnects thereby generating the highly resistive state. Angle-resolved photoemission spectroscopy spectra exhibit pseudogap behavior corroborating the spatial coexistence of gapped domains and narrow domain walls with excess charge carriers.

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Section: Emergent Network Of Narrow Transport Channelsmentioning

confidence: 95%

Metal-to-insulator transition in Pt-doped TiSe2 driven by emergent network of narrow transport channels

et al. 2021

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“…Many features of the UMass experiment have been confirmed by us in two separate experiments on solid samples of 8 µm and 2.5 mm in thickness [6,7]. Our study on 2.5 mm thick solid samples, carried out in 5 sample cells of different designs verifies the proposal of UMass's group by establishing a direct causal relation between mass flow and dislocation network in the solid; specifically we show mass flow takes place through, instead of around the solid sample contrary to that suggested by an experiment at the University of Alberta [8] and that no mass flow can be found in solid samples grown inside silica aerogel missing a dislocation network.…”

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confidence: 53%

Extinction and recovery of mass flow through solid He4 samples

Shin

Chan

2020

Phys. Rev. B

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Superfluid-like mass flow through 2 cm thick solid 4 He samples sandwiched between two porous Vycor glass rods filled with superfluid was observed in 2008. The flow commences below 0.6 K, increases in magnitude with decreasing temperature and shut-off abruptly below a temperature T d near 0.1 K. T d is found to increase with 3 He impurities at the few parts per million level. The mass flow phenomenon is recently reproduced in 8 µm thick solid samples; however, the shut-off of mass flow at low temperature is not seen. Here, we report measurements on 2.5 mm thick solid samples. Mass flow rate reduction and extinction near 0.1 K is found only when the concentration of the helium gas, X3, used to prepare the sample exceeds respectively 3.5 × 10 −4 and 2 × 10 −3 . After the extinction, the mass flow shows a gradual but complete recovery with a characteristic time of many hours. The experimental evidence allows us to formulate a model that explains both the extinction and recovery phenomena. The extinction of the mass flow is due to the trapping of 3 He atoms at the nodes or the intersections of the dislocation network which blocks the transport of 4 He along the network. The slow recovery in the 2.5 mm samples is due to the migration of the traooed 3 He atoms along the dislocation lines and drain into the superfluid inside the porous Vycor glass. Our model also explains naturally the absence of mass flow extinction in the 8 µm samples and the apparent absence of recovery in the 2 cm samples.

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“…However, in the latter experiment the mass flow extinction was absent. In the work [135] with solid samples of about 2 mm thickness, a typical flux of approximately 2.5 × 10 −8 g/mm 2 s is found. In general, it has been shown that thinner samples result in higher values of the flux, with the mass flow rate decreasing logarithmically with the thickness of the solid 4 He.…”

Section: Mass Flux Experimentsmentioning

confidence: 85%