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Mirzaei M, Vazifehshenas T, Salavati-Fard T, Tanatar B. Silicene dynamic optical response in the presence of external electric and exchange fields. J Phys Condens Matter 2022; 34:115301. [PMID: 34929675 DOI: 10.1088/1361-648x/ac44d4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
We investigate the dynamic optical transition of monolayer silicene in the presence of external electric and exchange fields within the low-energy tight-binding model. Applying external electric and exchange fields breaks the silicene band structure spin and valley degeneracies. Three phases of silicene corresponding to different strengths of perpendicular electric field with respect to the spin-orbit coupling (Δz< Δso, Δz= Δsoand Δz> Δso) are considered. We obtain the spin-valley-dependent optical responses to the incoming circularly polarized light using the Kubo formula. We show and discuss how the magnitude and direction of the transverse and longitudinal optical responses of such a system change with the electric and exchange fields. Our calculations suggest that the intraband part of the longitudinal optical response as well as the initial point of the interband part have strong dependencies on the exchange field. Furthermore, we show that one of the spin subbands plays a dominant role in the response to polarized light. Depending on the type of incident light polarization, the dominant subband may change. Our results shed light on the relation between silicene dynamic optical responses and externally applied fields.
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Affiliation(s)
- M Mirzaei
- Department of Physics, Shahid Beheshti University, G. C., Evin, Tehran 1983969411, Iran
| | - T Vazifehshenas
- Department of Physics, Shahid Beheshti University, G. C., Evin, Tehran 1983969411, Iran
| | - T Salavati-Fard
- School of Chemical, Biological and Materials Engineering, University of Oklahoma Norman, OK 73069, United States of America
| | - B Tanatar
- Department of Physics, Bilkent University, Bilkent, 06800 Ankara, Turkey
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Rakhimov A, Abdurakhmonov T, Tanatar B. Critical behavior of Tan's contact for bosonic systems with a fixed chemical potential. J Phys Condens Matter 2021; 33:465401. [PMID: 34407517 DOI: 10.1088/1361-648x/ac1ec6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 08/18/2021] [Indexed: 06/13/2023]
Abstract
The temperature dependence of Tan's contact parameterCand its derivatives for spin gapped quantum magnets are investigated. We use the paradigm of Bose-Einstein condensation (BEC) to describe the low temperature properties of quasiparticles in the system known as triplons. Since the number of particles and the condensate fraction are not fixed we use theμVTensemble to calculate the thermodynamic quantities. The interactions are treated at the Hartree-Fock-Bogoliubov approximation level. We obtained the temperature dependence ofCand its derivative with respect to temperature and applied magnetic field both above and belowTcof the phase transition from the normal phase to BEC. We have shown thatCis regular, while its derivatives are discontinuous atTcin accordance with Ehrenfest's classification of phase transitions. Moreover, we have found a sign change in ∂C/∂Tclose to the critical temperature. As to the quantum critical point,Cand its derivatives are regular as a function of the control parameterr, which induces the quantum phase transition. At very low temperatures, one may evaluateCsimply from the expressionC=m2μ2/a¯4, where the only parameter effective mass of quasiparticles should be estimated. We propose a method for measuring of Tan's contact for spin gapped dimerized magnets.
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Affiliation(s)
| | | | - B Tanatar
- Department of Physics, Bilkent University, Bilkent, 06800 Ankara, Turkey
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Roy S, Mishra T, Tanatar B, Basu S. Reentrant Localization Transition in a Quasiperiodic Chain. Phys Rev Lett 2021; 126:106803. [PMID: 33784113 DOI: 10.1103/physrevlett.126.106803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
Systems with quasiperiodic disorder are known to exhibit a localization transition in low dimensions. After a critical strength of disorder, all the states of the system become localized, thereby ceasing the particle motion in the system. However, in our analysis, we show that in a one-dimensional dimerized lattice with staggered quasiperiodic disorder, after the localization transition, some of the localized eigenstates become extended for a range of intermediate disorder strengths. Eventually, the system undergoes a second localization transition at a higher disorder strength, leading to all states being localized. We also show that the two localization transitions are associated with the mobility regions hosting the single-particle mobility edges. We establish this reentrant localization transition by analyzing the eigenspectra, participation ratios, and the density of states of the system.
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Affiliation(s)
- Shilpi Roy
- Department of Physics, Indian Institute of Technology Guwahati-Guwahati, 781039 Assam, India
| | - Tapan Mishra
- Department of Physics, Indian Institute of Technology Guwahati-Guwahati, 781039 Assam, India
| | - B Tanatar
- Department of Physics, Bilkent University, TR-06800 Bilkent, Ankara, Turkey
| | - Saurabh Basu
- Department of Physics, Indian Institute of Technology Guwahati-Guwahati, 781039 Assam, India
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Ţolea M, Moldoveanu V, Dinu IV, Tanatar B. Electronic transmittance phase extracted from mesoscopic interferometers. Nanoscale Res Lett 2012; 7:568. [PMID: 23061877 PMCID: PMC3583753 DOI: 10.1186/1556-276x-7-568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Accepted: 09/25/2012] [Indexed: 06/01/2023]
Abstract
: The usual experimental set-up for measuring the wave function phase shift of electrons tunneling through a quantum dot (QD) embedded in a ring (i.e., the transmittance phase) is the so-called 'open' interferometer as first proposed by Schuster et al. in 1997, in which the electrons back-scattered at source and the drain contacts are absorbed by additional leads in order to exclude multiple interference. While in this case one can conveniently use a simple two-path interference formula to extract the QD transmittance phase, the open interferometer has also a number of draw-backs, such as a reduced signal and some uncertainty regarding the effects of the extra leads. Here we present a meaningful theoretical study of the QD transmittance phase in 'closed' interferometers (i.e., connected only to source and drain leads). By putting together data from existing literature and giving some new proofs, we show both analytically and by numerical simulations that the existence of phase lapses between consecutive resonances of the 'bare' QD is related to the signs of the corresponding Fano parameters - of the QD + ring system. More precisely, if the Fano parameters have the same sign, the transmittance phase of the QD exhibits a Π lapse. Therefore, closed mesoscopic interferometers can be used to address the 'universal phase lapse' problem. Moreover, the data from already existing Fano interference experiments from Kobayashi et al. in 2003 can be used to infer the phase lapses.
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Affiliation(s)
- M Ţolea
- , National Institute of Materials Physics, P. O. Box MG-7, Bucharest-Magurele 77125, Romania
| | - V Moldoveanu
- , National Institute of Materials Physics, P. O. Box MG-7, Bucharest-Magurele 77125, Romania
| | - IV Dinu
- , National Institute of Materials Physics, P. O. Box MG-7, Bucharest-Magurele 77125, Romania
| | - B Tanatar
- Department of Physics, Bilkent University, Bilkent, Ankara 06800, Turkey
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Abedinpour SH, Polini M, MacDonald AH, Tanatar B, Tosi MP, Vignale G. Theory of the pseudospin resonance in semiconductor bilayers. Phys Rev Lett 2007; 99:206802. [PMID: 18233174 DOI: 10.1103/physrevlett.99.206802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Indexed: 05/25/2023]
Abstract
The pseudospin degree of freedom in a semiconductor bilayer gives rise to a collective mode analogous to the ferromagnetic-resonance mode of a ferromagnet. We present a many-body theory of the dependence of the energy and the damping of this mode on layer separation d. Based on these results, we discuss the possibilities of realizing transport-current driven pseudospin-transfer oscillators in semiconductors, and of using the pseudospin-transfer effect as an experimental probe of intersubband plasmons.
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Tanatar B. Trapped interacting Bose gas in nonextensive statistical mechanics. Phys Rev E Stat Nonlin Soft Matter Phys 2002; 65:046105. [PMID: 12005924 DOI: 10.1103/physreve.65.046105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2001] [Indexed: 05/23/2023]
Abstract
We study the Bose-Einstein condensation (BEC) phenomenon in an interacting trapped Bose gas using the semiclassical two-fluid model and nonextensive statistical mechanics. The effects of nonextensivity characterized by a parameter are explored by calculating the temperature dependent thermodynamic properties, fraction of condensed particles, and density distributions of condensed and thermal components of the system. It is found that nonextensivity in the underlying statistical mechanics may have large effects on the BEC transition temperature.
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Affiliation(s)
- B Tanatar
- Department of Physics, Bilkent University, Bilkent, 06533 Ankara, Turkey
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Asgari R, Davoudi B, Tanatar B. Hard-core Yukawa model for two-dimensional charge-stabilized colloids. Phys Rev E Stat Nonlin Soft Matter Phys 2001; 64:041406. [PMID: 11690025 DOI: 10.1103/physreve.64.041406] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2001] [Revised: 05/29/2001] [Indexed: 05/23/2023]
Abstract
The hypernetted chain and Percus-Yevick approximations are used to study the phase diagram of a simple hard-core Yukawa model of charge-stabilized colloidal particles in a two-dimensional system. We calculate the static structure factor and the pair distribution function over a wide range of parameters. Using static correlation functions, we present an estimate for the liquid-solid phase diagram for a wide range of parameters.
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Affiliation(s)
- R Asgari
- (IPM) Institute for Studies in Theoretical Physics and Mathematics, PO Box 19395-5531, Tehran, Iran
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Davoudi B, Kohandel M, Mohammadi M, Tanatar B. Hard-core yukawa model for charge-stabilized colloids. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 2000; 62:6977-6981. [PMID: 11102053 DOI: 10.1103/physreve.62.6977] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2000] [Indexed: 05/23/2023]
Abstract
The hypernetted chain approximation is used to study the phase diagram of a simple hardcore Yukawa model of a charge-stabilized colloids. We calculate the static structure factor, the pair distribution function, and the collective mode energies over a wide range of parameters, and the results are used for studying the freezing transition of the system. The resulting phase diagram is in good agreement with the known estimates and the Monte Carlo simulations.
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Affiliation(s)
- B Davoudi
- Institute for Studies in Theoretical Physics and Mathematics, Tehran 19395-5531, Iran
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Tanatar B, Güven K, Bennett CR, Constantinou NC. Screening effects on the confined and interface polarons in cylindrical quantum wires. Phys Rev B Condens Matter 1996; 53:10866-10870. [PMID: 9982657 DOI: 10.1103/physrevb.53.10866] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Tanatar B, Gold A. Correlation effects in the impurity-limited mobility of quantum wires. Phys Rev B Condens Matter 1995; 52:1996-2000. [PMID: 9981268 DOI: 10.1103/physrevb.52.1996] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Hakioglu T, Ivanov VA, Shumovsky AS, Tanatar B. Phonon squeezing via correlations in the superconducting electron-phonon interaction. Phys Rev B Condens Matter 1995; 51:15363-15368. [PMID: 9978494 DOI: 10.1103/physrevb.51.15363] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Tanatar B. High-frequency damping of plasmons in quasi-one-dimensional electron systems. Phys Rev B Condens Matter 1995; 51:14410-14413. [PMID: 9978372 DOI: 10.1103/physrevb.51.14410] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Chui ST, Tanatar B. Impurity effect on the two-dimensional-electron fluid-solid transition in zero field. Phys Rev Lett 1995; 74:458-461. [PMID: 10058763 DOI: 10.1103/physrevlett.74.458] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Tanatar B, Constantinou NC. Collective excitations in quasi-one-dimensional electron systems under a magnetic field. Phys Rev B Condens Matter 1993; 48:18280-18283. [PMID: 10008475 DOI: 10.1103/physrevb.48.18280] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Shumovsky AS, Tanatar B. Quantum-statistical properties of a Raman-type model. Phys Rev A 1993; 48:4735-4741. [PMID: 9910183 DOI: 10.1103/physreva.48.4735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Tanatar B. Screened bulk electron-phonon interactions in quantum-well wires. Phys Rev B Condens Matter 1993; 48:12001-12007. [PMID: 10007546 DOI: 10.1103/physrevb.48.12001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Tanatar B. Dynamic response of two-dimensional electron liquids in the local-density-functional theory. Phys Rev B Condens Matter 1992; 46:1347-1350. [PMID: 10003774 DOI: 10.1103/physrevb.46.1347] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Grynberg MD, Tanatar B. Square Ising model with second-neighbor interactions and the Ising chain in a transverse field. Phys Rev B Condens Matter 1992; 45:2876-2882. [PMID: 10001837 DOI: 10.1103/physrevb.45.2876] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Tanatar B. Phenomenological investigations of S(k, omega ) of the two-dimensional electron gas in the memory-function formalism. Phys Rev B Condens Matter 1991; 43:14621-14628. [PMID: 9997354 DOI: 10.1103/physrevb.43.14621] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Tanatar B, Singh M. Temperature dependence of the cyclotron-resonance linewidth and effective mass in GaAs/Ga1-xAlxAs square-well structures. Phys Rev B Condens Matter 1991; 43:6612-6619. [PMID: 9998103 DOI: 10.1103/physrevb.43.6612] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Tanatar B, Singh M, MacDonald AH. Self-consistent Landau-level broadening by acoustic phonons in two-dimensional electron systems. Phys Rev B Condens Matter 1991; 43:4308-4316. [PMID: 9997783 DOI: 10.1103/physrevb.43.4308] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Tanatar B, Singh M. Phonon-assisted cyclotron resonance in n-type quantum-well structures. Phys Rev B Condens Matter 1990; 42:3077-3081. [PMID: 9995803 DOI: 10.1103/physrevb.42.3077] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Singh M, Tanatar B. Phonon-assisted magneto-optical transitions in two-dimensional systems. Phys Rev B Condens Matter 1990; 41:12781-12786. [PMID: 9993754 DOI: 10.1103/physrevb.41.12781] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Tanatar B, Talbot EF, Glyde HR. Oscillations and line shapes of S(Q, omega ) in quantum fluids. Phys Rev B Condens Matter 1987; 36:2425-2428. [PMID: 9943120 DOI: 10.1103/physrevb.36.2425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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