Long-wavelength quantum and classical plasma frequencies in fractional-dimensional space

Panda, Subhashree; Panda, B. K.

doi:10.1088/0953-8984/20/48/485201

Cited by 7 publications

(5 citation statements)

References 63 publications

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“…Recently, we have derived an interpolating formula for μ of the noninteracting Fermi gas in the FD space valid in the high-temperature limit at an arbitrary density of particles [19]. In the present work, we will present the derivation of μ valid for low-temperature and high-density limits only.…”

Section: Methods Of Calculationmentioning

confidence: 99%

“…The anisotropic lowdimensional space in 3D structures becomes isotropic in the FD space and the dimension provides a measure for the degree of anisotropy in the actual physical system. The dimension is determined from the extension of radius of bosons such as exciton [16], polaron [17], exciton-polaron [18] and plasmon [19] with respect to the well width in quantum well and the square root of the internal area in quantum wire [20]. The quasi-2D layered structures of high-temperature superconducting thin films are actually not 2D objects, but fractals with Hausdorff dimensionalities between 2D and 3D in the real laboratory situation [21,22].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Chemical potential and internal energy of the noninteracting Fermi gas in fractional-dimensional space

Panda¹,

Panda²

2010

Pramana - J Phys

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Chemical potential and internal energy of a noninteracting Fermi gas at low temperature are evaluated using the Sommerfeld method in the fractional-dimensional space. When temperature increases, the chemical potential decreases below the Fermi energy for any dimension equal to 2 and above due to the small entropy, while it increases above the Fermi energy for dimensions below 2 as a result of high entropy. The ranges of validity of the truncated series expansions of these quantities are extended from low to intermediate temperature regime as well as from high to relatively low density regime by using the Padé approximant technique.

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Section: Methods Of Calculationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Chemical potential and internal energy of the noninteracting Fermi gas in fractional-dimensional space

Panda¹,

Panda²

2010

Pramana - J Phys

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“…For each value of the Fermi energy E F , we extract the electronic temperature T e from the experimental curve in Fig. 1D and derive the chemical potential µ on the base of a free electron model 32 . The value of Γ em and Γ abs strongly depend on the electron-phonon coupling strength of the polar modes.…”

Section: Pacs Numbersmentioning

confidence: 99%

Ultrafast dynamics of hot carriers in a quasi–two-dimensional electron gas on InSe

Chen

Sjakste

Dong

et al. 2020

Proc. Natl. Acad. Sci. U.S.A.

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Two-dimensional electron gases (2DEGs) are at the base of current nanoelectronics because of their exceptional mobilities. Often the accumulation layer forms at polar interfaces with longitudinal optical (LO) modes. In most cases, the many-body screening of the quasi-2DEGs dramatically reduces the Fröhlich scattering strength. Despite the effectiveness of such a process, it has been recurrently proposed that a remote coupling with LO phonons persists even at high carrier concentration. We address this issue by perturbing electrons in an accumulation layer via an ultrafast laser pulse and monitoring their relaxation via time- and momentum-resolved spectroscopy. The cooling rate of excited carriers is monitored at doping level spanning from the semiconducting to the metallic limit. We observe that screening of LO phonons is not as efficient as it would be in a strictly 2D system. The large discrepancy is due to the remote coupling of confined states with the bulk. Our data indicate that the effect of such a remote coupling can be mimicked by a 3D Fröhlich interaction with Thomas–Fermi screening. These conclusions are very general and should apply to field effect transistors (FET) with high-κ dielectric gates, van der Waals heterostructures, and metallic interfaces between insulating oxides.

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“…For D>2, however, conditions for which no bound states exist, can be identified. To this end, we follow [40] in order to relate screening to the Fermi level E F of free carriers. Considering doping by electrons in the effective mass approximation, one has (in natural units) [40]…”

Section: Application To Quantum Wellsmentioning

confidence: 99%

Yukawa model of screening in low-dimensional excitons: diagonalization, perturbation, variation, and resummation analysis

Pedersen

2019

J. Phys. Commun.

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The Yukawa interaction describes Coulomb screening in several physical systems. We investigate bound quantum states of the Yukawa potential in low-dimensional structures as a model of e.g. excitons in semiconductor nanostructures. Diagonalization, perturbation, variation, and resummation methods are all applied to the problem and their accuracy is compared. For moderate positive screening, all methods are found to be applicable and, in particular, the variational approach is highly accurate except near the threshold for bound states. In contrast, only hypergeometric resummation captures the correct behaviour in the negative (antiscreened) regime. We also determine the dimensional dependence of the critical screening, above which bound states cease to exist. As an application, the critical screening is used to compute critical doping levels for the existence of bound excitons in quantum wells.

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Long-wavelength quantum and classical plasma frequencies in fractional-dimensional space

Cited by 7 publications

References 63 publications

Chemical potential and internal energy of the noninteracting Fermi gas in fractional-dimensional space

Chemical potential and internal energy of the noninteracting Fermi gas in fractional-dimensional space

Ultrafast dynamics of hot carriers in a quasi–two-dimensional electron gas on InSe

Yukawa model of screening in low-dimensional excitons: diagonalization, perturbation, variation, and resummation analysis

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