Quantum Hall composite resonator
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A Quantum Hall composite resonator (QHCR) is a topological object with quantum reactive parameters (CR and LR), that have fixed resonant frequency (?), due to the odd number of electrons which are moving in the homogenous magnetic field (B). QHCR has characteristic impedance proportional to the von Klitzing constant (RK = h / e2 = 25.8128 kOhm), the odd number of electrons (j = 3,5,7,...) and to the reverse Landau level number (i = 1,2,3,...):
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[edit] History
The discovery of the Quantum Hall effect by Klaus von Klitzing in 1980[1] was completely unexpected, as nobody considered that a macroscopic physical value as such as electrical resistance could be quantized. Robert B. Laughlin proposed a simple quantum theory in 1981 [2] which explained the quantization of resistance in terms of one-electron filling of Landau levels in a strong magnetic field which caused the electrons of a material to move in circles. Furthermore, the semiclassical Hall current in this approach is due to the adiabatic derivative of the total system energy by magnetic flux through the closed loop. This approach, however, does not take into consideration the electric fields, which can be strong in certain conditions (especially in semiconductor devices such as MOSFETs), and does nothing with the reactive parameters of the Quantum LC Circuit formed.Template:Clarify me
The situation becomes more complicated when Horst Ludwig Stormer, Daniel C. Tsui, and Arthur Gossard discovered [3] the fractional quantum Hall effect. The simple quantum theory of Laughlin would consider the "carriers" of fractional charge,[4] as composite fermions.[5][6][7] Further developments was made by S.H. Simon in 1998.[8] In this approach, Landau levels are filled by composite fermions which have fractional charges, and other shortages are the same as the QHE Laughlin model has.Template:Clarify me The Laughlin-Jain-Simon approach is the dominant view now, but some physicists strongly criticize it. For example, Keshav N. Shrivastava thought that quasiparticles formed the quantum of magnetic flux (Template:Nowrap), which could be connected to an electron forming a compound state with some magnetic and electric flux quantum.[9][10] The theory of such quasiparticles could not be derived from first principles.
Furthermore, M.I. Dyakonov [11] described the current situation as being inconvenient: on one hand, there are many experimental facts which confirm the idea of composite fermions that takes part in the "singular" theoretical approach to the phenomenon, which hints at the physical reality of the idea, but on the other hand, nobody can theoretically justify the existence of these free quasiparticles.
However, there is another approach to the FQHE. At the beginning of the 21st century, Raphael Tsu proposed a new conception of quantum mechanics[12] in which the characteristic impedance [13] Template:Clarify me plays the dominant role. This dominance was illustrated in the quantum oscillator problem by Yakov Zel'dovich in 2008.[14] But Tsu and Zel'dovich were not the firsts.Template:Clarify me
It so happens that there is little interest in macroscopic properties such as resistance, capacitance, and inductance in the modern quantum electrodynamics. Furthermore, these properties are neglected even in classical electrodynamics, in favour of concepts such as electric and magnetic fields. For example, Maxwell equations is formulated in terms of fields and so the resulting solutions only include fields. "Field approaches" in electrodynamics that consider "point charges" leads to mathematical singularities (renormalization problems) when the interaction radius trends to zero. Furthermore, these singularities are present in quantum electrodynamics too, where power methods are developed to compensate. In applied physics, reactive parameters are such as capacitance and inductance are used instead of fields.
The present day situation (without proper development of the theory of reactive parameters such as inductance, capacitance and electromagnetic resonator) impedes developments of information technologies and quantum computing.The mechanical harmonic oscillator was studied in the early 1930s, when the quantum theory was first developed. However, the quantum consideration of the LC circuit was started only by Louisell in 1973.[15] Since then, there were no practical examples of quantum capacitances and inductances, therefore this approach did not received much consideration. Theoretically correct introductions of the quantum capacitance for QHE, based on the density of states, were first presented by Serge Luryi in 1988.[16]. However, Luryi did not introduce the quantum inductance, and this approach was not considered in the quantum LC circuit and resonator. One year later, O.L. Yakymakha[17] considered an example of the series and parallel QHE LC circuits (both integer and fractional) and their characteristic impedances. However he did not conside the Schrodinger equation for the quantum LC circuit.
For the first time, both quantum values, capacitance and inductance, were considered by Yakymakha in 1994,[18] during spectroscopic investigations of MOSFETs at the very low frequencies (sound range). The flat quantum capacitances and inductances here had thicknesses about Compton wave length of electron and its characteristic impedance – the wave impedance of free space. Three year later, Devoret presented a complete theory of the quantum LC Circuit (applied to the Josephson junction).[19] Possible application of the quantum LC circuits and resonators in quantum computations were considered by Devoret in 2004.[20]
[edit] Quantum resonator general approach
[edit] Quantum Hall resonator (QHR)
Magnetic length:
where
reduced Planck constant,
electron charge, and
external homogenous magnetic field (induction).
Surface scaling parameter:
Cyclotron frequency:
where
effective electron mass in solids.
QHR density of states (DOS):
where qR − is electric flux through the surface
. DOS quantum inductance:
where φR − is magnetic flux through the surface
. Considering quantum oscillations in the resonator, these fluxes are the "amplitude values" only, and they does not quantized. Maximal value of the capacitance energy:
Maximal value of the inductance energy:
QHR resonance frequency:
Standard quantum oscillator has the following eigen values of the Hamiltonian:
where at
we shall have zero oscillation:
QHR energy conservation law (at n = 0):
which yields the following relationship between the fluxes (an analog of Heisenberg uncertainty principle for fluxes):
QHR characteristic impedance:
The solution of these two equation yields the following values for electric and magnetic fluxes:
where
is magnetic flux quantum.
where
electric fine structure constant,
magnetic fine structure constant,
dielectric constant,
magnetic constant, and
Compton wavelength of electron. Note that, the QHR resonance frequency takes the values of cyclotron frequency here:
[edit] Quantum composite resonator formation
[edit] Direct step
Let us consider the standard QHE one electron filling Landau levels step by step at constant magnetic field
and increasing electric field
Surface electron concentration here will be at the first Landau level:
First Landau level energy:
where
is the cyclotron frequency due to the constant magnetic field
.
With increasing filling number
we shall have the following parameters of QHR: Surface electron concentration:
Landau level energy:
Density of states:
Induced electric flux:
DOS quantum capacitance:
So, we have the parallel connection of “elementary resonator” quantum capacitances in that case.
Induced magnetic flux:
DOS quantum inductance:
So, we have the series connection of “elementary resonator” quantum inductances in that case.
Characteristic impedance:
Resonance frequency:
Thus, in the constant homogenous magnetic field with one electron filling Landau level we shall have the following conservating parameters:
[edit] Reverse step
Let us consider the reverse case when electric field is constant (
), and increasing magnetic field:
where
the maximal number of electron on Landau level (or integer number that consider reducing the surface scaling parameter ).
The maximum value of Landau level at the first direct step (or electron number which consider electrons that take place in the QHE):
For the sake of the unitary consideration it is need to redefine parameters of the first stage future composite resonator. Surface electron concentration:
Landau level energy:
Density of states:
Induced electric flux:
DOS quantum capacitance:
Induced magnetic flux:
DOS quantum inductance:
Characteristic impedance:
Resonance frequency:
Thus, we are ready to consider the second case at
,
and
. Note that with increasing magnetic field to
the second electron from the second Landau level go to the first Landau level filled by the first electron, and the third electron go to the second Landau level. So, we have the composite resonator with two filled Landau levels.
DOS quantum capacitance in that case will be:
where
The total energy of this composite resonator will be:
at
Density of states will be:
The natural supposition for surface electron density
yields the following value for DOS in that case:
DOS quantum inductance:
where induced magnetic flux is considered:
Characteristic impedance in that case will be:
Resonance frequency:
Now we are ready to consider the third case at
,
and
. Note that, with increasing magnetic field to
the third electron from the second Landau level go to the first Landau level filled by the first and second electrons. So, we have the composite resonator with one filled Landau level by three electrons. DOS quantum capacitance in that case will be:
The total energy of this composite resonator will be:
at
Density of states will be:
The natural supposition for surface electron density
yields the following value for DOS in that case:
So, the new composite system returns to the natural 2D- case (or the CQR system returns to the "beginning"). DOS quantum inductance:
where induced magnetic flux is considered:
Characteristic impedance in that case will be:
Resonance frequency:
Thus, the composite quantum Hall resonator is formed. The per Landau level energy:
The energy gap of QCHR:
Now the QHCR could be considered as "elementary quantum object" for the external magnetic and electric fields, independently of its intrinsic structure. Note that, this object is connected to three metallurgic electrons and could change its state simultaneously.
[edit] QHCR and fractional QHE
Now we can consider the s.c. fractional QHE by the composite resonator model formed by "three electrons". As in the case of one electron resonator model we should to fix magnetic field:
,
and increase electric field:
So, the filling Landau level number
will be connected with "tree electrons" for every Landau level. Surface electron concentration will be here:
Density of states will be:
Induced electric flux:
DOS quantum capacitance:
Induced magnetic flux:
DOS quantum inductance:
Characteristic impedance in that case will be:
where
QHCR resonance frequency:
Note that, in the general case filling number :
could be connected with any odd quantiity of filling electrons per Landau level (
). However, in that cases we shall have another values for characteristic impedance and resonance frequency:
[edit] Quantum antidot
Resonance electron tunelling [21] in the Goldmat quantum antidot [22] could be investigated experimentally by measuring periodic quantuzatin (oscillation) of magnetic and electric fields:
where
- Landau level number, and
- electron number of composite resonator.
Electric field in the quantum antidot can be represented through applied voltage:
where
is the dielectric constant,
is the relative permittivity,
heterojunction thickness, and
heterojunction mesoscopic capacitance per unit area.
Electric and magnetic flux quantization are due to the properties of composite resonator formed in the quantum antidot:
Characteristic impedunce of composite resonator is:
Now we can find out the relationship between electric voltage and magnetic field quantization:
Thus, there are no any fractional electric charges in the quantum antidot. The number of tunelling electron is due to the Landau level number (
). But the number of magnetic flux quantum is due to the electron in the composite resonator (
).
[edit] Unconventional integer QHE in graphene
[edit] History
First, the unconventional integer QHE was discovered in graphene by Novoselov et. al. [23] and Zhang et al.(2005)[24]. Theoretical interpretation was proposed by Sharapov et.al.[25] [26]. The point is that conductance quantization has anomaly at the first Landau level, due to a twice smaller degeneracy. Furthermore, the first Landau level is filled by electron and hole quasiparticles simultaneously. Similar phenomena were presented in the classical case in silicon MOSFETs, when the last are working in the weak inversion mode first considered by Swanson (1972)[27] and further modernized by Yakymakha (1981) [28]. The only difference between graphene and silicon devices is that MOSFETs are the monopolarar devices (due to the p-n- junctions of source and drain).
The room-temperature quantum galvanomagnetic effects in the 2D-systems consisting of the two sort particles was predicted by Yakymakha (1989)[17].
First experimental confirmation of the room-temperature QHE were obtained in graphene by Novoselov et.al. (2007)[29]. This is due to the highly unusual nature of charge carriers in graphene, which behave as massless relativistic particles (Dirac fermions) and move with little scattering under ambient conditions.
[edit] Graphene QHE composite resonator
The standard characteristic impedance of the electron quantum Hall resonator in graphen is:
where gn is the electron degeneration number due to the band structure of graphene. The standard characteristic impedance of the hole quantum Hall resonator in graphen is:
where gp = gn = g = 4 is the hole degeneration number due to the band structure of graphene.
At the first Landau level both, electrons and holes are filling the same 2D surface (something like chessboard).
So, the elementary composite resonator here will be formed by one electron and one hole. The total inductance of this resonator will be consisted of the electron and hole inductances connected in series:
By analogy, the total capacitance of this resonator will be consisted of the electron and hole capacitances connected in series:
Thus, the total characteristic impedance of the composite resonator will be as follows:
where g = 4.
The second Landau level is filled by monopolar particles (electrons or holes). Therefore, the total characteristic impedance of the second Landau level will be consisted of the first composite resonator and second standard resonator connected in parallel:
where σHg = g / RH is the conductance quantum for graphene. For the third Landau level and hihger we would have the following total characteristic impedance:
where i is the Landau level number.
[edit] See also
[edit] References
- ↑ von Klitzing, K. (1980). "New Method for High-Accuracy Determination of the Fine-Structure Constant Based on Quantized Hall Resistance". Physical Review Letters 45 (6): 494–497. doi:10.1103/PhysRevLett.45.494.
- ↑ Laughlin, R. B. (1981). "Quantized Hall conductivity in two dimensions". Physical Review B 23 (10): 5632–5633. doi:10.1103/PhysRevB.23.5632.
- ↑ Tsui, D.C. (1982). "Two-Dimensional Magnetotransport in the Extreme Quantum Limit". Physical Review Letters 48. doi:10.1103/PhysRevLett.48.1559.
- ↑ Laughlin, R.B. (1983). "Anomalous Quantum Hall Effect: An Incompressible Quantum Fluid with Fractionally Charged Excitations". Physical Review Letters 50. doi:10.1103/PhysRevLett.50.1395.
- ↑ Jain, J.K. (1989). "Composite-fermion approach for the fractional quantum Hall effect". Physical Review Letters 63. doi:10.1103/PhysRevLett.63.199.
- ↑ Jain, J.K. (1989). "{{{title}}}". Physical Review B 40.
- ↑ Jain, J.K. (1990). "Theory of the fractional quantum Hall effect". Physical Review B 41. doi:10.1103/PhysRevB.41.7653.
- ↑ Template:Cite arxiv
- ↑ Template:Cite arxiv
- ↑ Template:Cite arxiv
- ↑ Template:Cite arxiv
- ↑ Template:Cite arxiv
- ↑ Raphael Tsu and Timir Datta (2008) “Conductance and Wave Impedance of Electrons”. Progress In Electromagnetics Research Symposium, Hangzhou, China, March 24-28 Pdf
- ↑ Zel'dovich, B.Y. (2008). "Impedance and parametric excitation of oscillators". UFN 178 (5).
- ↑ Louisell, W. H. (1973). Quantum Statistical Properties of Radiation. Wiley (publisher).
- ↑ Luryi, S. (1988). "Quantum capacitance device". Applied Physics Letters 52 (6): 501. doi:10.1063/1.99649.
- ↑ 17.0 17.1 Yakymakha, O.L. (1989). High Temperature Quantum Galvanomagnetic Effects in the Two- Dimensional Inversion Layers of MOSFET's. Kyiv: Vyscha Shkola.
- ↑ Yakymakha, O.L. (1994). "Very-low-frequency resonance of MOSFET amplifier parameters". Solid State Electronics 37 (10): 1739–1751. doi:10.1016/0038-1101(94)00152-6.
- ↑ Deboret, M.H. (1997). Quantum Fluctuations. Elsevier, 351–386.
- ↑ Devoret, M.H. (2004). "Implementing Qubits with Superconducting Integrated Circuits". Quantum Information Processing 3 (1). doi:10.1007/0-387-27732-3.
- ↑ S. Luryi, A. Zaslavsky. CHAPTER 5. QUANTUM-EFFECT AND HOT-ELECTRON DEVICES
- ↑ V.J.Goldman and B.Su "Resonant Tunneling in Quantum Hall Effect: Measurement of Fractional Charge". Science 267, 1010-1012 (1995)
- ↑ Novoselov, K. S. (2006). "Unconventional quantum Hall effect and Berry's phase of 2-pi in bilayer graphene". Nature Physics 2: 177 - 180. doi:10.1038/nphys245.
- ↑ Zhang, Y. (2005). "Experimental observation of the quantum Hall effect and Berry’s phase in graphene". Nature 438: 201. doi:10.1038/nature04235.
- ↑ Template:Cite arxiv
- ↑ Gusynin, V.P. (2005). "Unconventional Integer Quantum Hall Effect in Graphene". Physical Review Letters 95. doi:10.1103/PhysRevLett.95.146801.
- ↑ Swanson, R.M. (1972). "Ion- implanted complementary MOS- transistor in low- voltages circuits". IEEE Journal SC-7 (2): 146-153.
- ↑ Yakymakha, O.L. (1981). "An addition to the static MOSFET model in the weak inversion //Об уточнении статической модели МДП- транзистора в микрорежиме (in Russian)". Радиотехника 36 (10): 9-15.
- ↑ Novoselov, K. S. (2007). "Room-Temperature Quantum Hall Effect in Graphene". Science 315: 1379. doi:10.1126/science.1137201.
[edit] Reference Books
- Stratton J.A.(1941). Electromagnetic Theory. New York, London: McGraw-Hill.p.615. djvu
- Детлаф А.А., Яворский Б.М., Милковская Л.Б.(1977). Курс физики. Том 2. Электричество и магнетизм (4-е издание). М.: Высшая школа, "Reference Book on Electricity" djvu
- Гольдштейн Л.Д., Зернов Н.В. (1971). Электромагнитные поля. 2- издание. Москва: Советское Радио. 664с. "Electromagnetic Fields" djvu
- Zyun F. Ezawa: Quantum Hall Effects - Field Theoretical Approach and Related Topics. World Scientific, Singapore 2008, ISBN 978-981-270-032-2
- Sankar D. Sarma, Aron Pinczuk: Perspectives in Quantum Hall Effects. Wiley-VCH, Weinheim 2004, ISBN 978-0-471-11216-7
- Composite Fermions, Edited by O. Heinonen, World Scientific, Singapore (1998).
























































































