Universal Behavior of the Resistance Noise across the Metal-Insulator Transition in Silicon Inversion Layers

Jaroszyński, J.; Popović, Dragana; Klapwijk, T. M.

doi:10.1103/physrevlett.89.276401

Cited by 95 publications

(175 citation statements)

References 39 publications

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“…In the vicinity of the apparent metal-insulator transition (MIT), in particular, both electron-electron interactions and disorder appear to be equally important. [2,3] are consistent with the model of glassy behavior that occurs in the charge sector [5,8,9], it is still an open question whether charge or spin degrees of freedom are responsible for the observed glass transition. Since a sufficiently strong magnetic field is expected to destroy the spin glass order [7,10], experimental studies of glassy dynamics in parallel magnetic fields B [11] should be able to distinguish between the proposed models.…”

supporting

confidence: 74%

“…Here we present such a study, which shows that the glass transition persists even in B such that the 2D system is spin polarized. These results demonstrate that charge, as opposed to spin, degrees of freedom are responsible for glassy ordering of the 2DES near the MIT.Previous studies carried out at B = 0 employed a combination of transport and low-frequency resistance noise measurements [2,3] to probe the glassy behavior. The glass transition was manifested by a sudden and dramatic slowing down of the electron dynamics and by an abrupt change to the sort of statistics characteristic of complicated multistate systems, consistent with the hierarchical picture of glassy dynamics.…”

mentioning

confidence: 59%

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Glassy behavior of a two-dimensional electron system in Si in parallel magnetic fields

2004

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Studies of low-frequency resistance noise show that the glassy freezing of the two-dimensional electron system (2DES) in Si in the vicinity of the metal-insulator transition (MIT) persists in parallel magnetic fields B of up to 9 T. At low B, both the glass transition density ng and nc, the critical density for the MIT, increase with B such that the width of the metallic glass phase (nc < ns < ng) increases with B. At higher B, where the 2DES is spin polarized, nc and ng no longer depend on B. Our results demonstrate that charge, as opposed to spin, degrees of freedom are responsible for glassy ordering of the 2DES near the MIT.PACS numbers: 71.30.+h, 71.27.+a, 73.40.Qv The fascinating strong correlation physics exhibited by low-density two-dimensional (2D) electron and hole systems [1] remains the subject of intensive research. In the vicinity of the apparent metal-insulator transition (MIT), in particular, both electron-electron interactions and disorder appear to be equally important. [2,3] are consistent with the model of glassy behavior that occurs in the charge sector [5,8,9], it is still an open question whether charge or spin degrees of freedom are responsible for the observed glass transition. Since a sufficiently strong magnetic field is expected to destroy the spin glass order [7,10], experimental studies of glassy dynamics in parallel magnetic fields B [11] should be able to distinguish between the proposed models. Here we present such a study, which shows that the glass transition persists even in B such that the 2D system is spin polarized. These results demonstrate that charge, as opposed to spin, degrees of freedom are responsible for glassy ordering of the 2DES near the MIT.Previous studies carried out at B = 0 employed a combination of transport and low-frequency resistance noise measurements [2,3] to probe the glassy behavior. The glass transition was manifested by a sudden and dramatic slowing down of the electron dynamics and by an abrupt change to the sort of statistics characteristic of complicated multistate systems, consistent with the hierarchical picture of glassy dynamics. It was also found [2] that the glass transition occurs in the metallic phase, i.e. at an electron density n g > n c , where n c is the critical density for the MIT determined from the vanishing of activation energy in the insulating regime [12,13]. The intermediate metallic glass (MG) phase is of considerable width in strongly disordered samples ((n g − n c )/n c ≈ 0.5 [2]), whereas in devices with low disorder n g is only a few percent higher than n c [3], in agreement with theory [9]. In this work, we investigate the glass transition in these same high peak mobility (low disorder) devices using noise spectroscopy in a parallel B. We find that all the signatures of the glass transition in parallel B are qualitatively the same as in B = 0, even when the electrons are spin polarized at high B. We construct a phase diagram in the (n s , B) plane (n s is the electron density), and find that the MG phase is broadene...

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supporting

confidence: 74%

mentioning

confidence: 59%

Glassy behavior of a two-dimensional electron system in Si in parallel magnetic fields

2004

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“…A linear high temperature behavior Γ ∼ T − T 0 was indeed observed experimentally 58 . Equation (21) further predicts the interesting relation T 0 = dE(1 − ρ(E)/ν 0 d)/4 ln 2, which allows to determine experimentally the width of the Coulomb gap.…”

Section: B Instability Criterion and Breakdown Of Memorymentioning

confidence: 85%

“…The anomalous resistance fluctuations observed in ultrathin granular aluminium films 14 and silicon MOSFETs close to the metal insulator transition 20,21 were also interpreted as indications for glassy behavior. Unfortunately, in these systems, it is difficult to disentangle effects due to intrinsically glassy behavior of interacting electrons from the strong response of the percolating network of hopping electrons to extrinsic slow degrees of freedom.…”

Section: Insulatormentioning

confidence: 94%

Memory effect in electron glasses: Theoretical analysis via a percolation approach

Lebanon

Müller

2005

Phys. Rev. B

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We present a theory for the memory effect in electron glasses. In fast gate voltage sweeps it is manifested as a dip in the conductivity around the equilibration gate voltage. We show that this feature, also known as anomalous field effect, arises from the long-time persistence of correlations in the electronic configuration. We argue that the gate voltage at which the memory dip saturates is related to an instability caused by the injection of a critical number of excess carriers. This saturation threshold naturally increases with temperature. On the other hand, we argue that the gate voltage beyond which memory is erased, is temperature independent. Using standard percolation arguments, we calculate the anomalous field effect as a function of gate voltage, temperature, carrier density and disorder. Our results are consistent with experiments, and in particular, they reproduce the observed scaling of the width of the memory dip with various parameters.

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“…These issues in a Coulomb glass have been reviewed recently [2]. The experimental investigations on these questions are few and were carried out only in the doped semiconductors with electron density close to the critical concentration (n C ) for metal-insulator (MI) transition [7,8] or in 2DEG in MOSFET's [9]. Here, we focus on the issue of non-Gaussian low frequency noise in the Coulomb glass state of a very different material, namely the low hole-doped rare-earth manganites which can have a ferromagnetic insulating (FMI) state below a certain temperature (T ).…”

mentioning

confidence: 99%

Non-Gaussian resistance noise in the ferromagnetic insulating state of a hole-doped manganite

2012

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We report the observation of a large 1/f noise in the ferromagnetic insulating state (FMI) of a hole doped manganite single crystal of La0.80Ca0.20MnO3 which manifests hopping conductivity in presence of a Coulomb gap. The temperature dependent noise magnitude shows a deep within the FMI state, there is a sharp freeze out of the noise magnitude with temperature on cooling. As the material enters the FMI state, the noise becomes non-Gaussian as seen through probability density function and second spectra. It is proposed to arise from charge fluctuations in a correlated glassy phase of the polaronic carriers which develop in these systems as reported in recent simulation studies.PACS numbers: 71.30.+h, 71.27.+a, 72.70.+m Electronic transport through localized states in disordered and correlated electronic systems has been a topic of considerable interest [1,2]. In such systems, long range Coulomb interaction can lead to opening-up of a soft gap in the density of states (referred to as Coulomb gap, ∆ CG ) and hopping conduction in presence of such a gap [3]. Another consequence is emergence of "glassy" slow relaxations of charge carriers arising from a large number of low-lying states separated by barriers [4]. Such a glassy state can lead to enhanced low frequency (f ) non-Gaussian resistance noise (typically with power spectrum varying as 1/f ) arising from charge fluctuations [5,6]. These issues in a Coulomb glass have been reviewed recently [2]. The experimental investigations on these questions are few and were carried out only in the doped semiconductors with electron density close to the critical concentration (n C ) for metal-insulator (MI) transition [7,8] or in 2DEG in MOSFET's[9]. Here, we focus on the issue of non-Gaussian low frequency noise in the Coulomb glass state of a very different material, namely the low hole-doped rare-earth manganites which can have a ferromagnetic insulating (FMI) state below a certain temperature (T ). In these systems, the Coulomb glass phase occurs for the localized polaronic carriers (in sharp contrast to doped semiconductors) which arise due to strong electron-phonon coupling arising from JahnTeller distortion around the Mn 3+ ions.The FMI state of hole doped manganites (La 1−x Ca x MnO 3 ) arises when hole concentration x in LaMnO 3 exceeds the critical concentration for * email: sudeshna@bose.res.in † email: arup@bose.res.in, ferromagnetism x ≈ 0.15 yet it is smaller than the concentration needed for the formation of the metallic ground state x ≥ x C = 0.22. Existence of a Coulomb glass behavior in the FMI state has been inferred from certain transport experiments [10,11] and also predicted theoretically recently [12]. The FMI state in manganite is unique [13]. We observe a large low frequency resistance fluctuations (noise) with non-trivial T dependence in the FMI state and the noise becomes non-Gaussian at temperatures below the onset of the insulating state. At low T well below the transition to the insulating state the noise shows a sharp fall on cooling. We pr...

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Universal Behavior of the Resistance Noise across the Metal-Insulator Transition in Silicon Inversion Layers

Cited by 95 publications

References 39 publications

Glassy behavior of a two-dimensional electron system in Si in parallel magnetic fields

Glassy behavior of a two-dimensional electron system in Si in parallel magnetic fields

Memory effect in electron glasses: Theoretical analysis via a percolation approach

Non-Gaussian resistance noise in the ferromagnetic insulating state of a hole-doped manganite

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