Fractional quantum Hall effect and duality Dam Thanh Son (University of Chicago) Strings 2017, Tel Aviv, Israel June 26, 2017. The electron localization is realized by the long-range potential fluctuations, which are a unique and inherent feature of quantum Hall systems. PDF. Recent research has uncovered a fascinating quantum liquid made up solely of electrons confined to a plane surface. Hall effect for a fractional Landau-level filling factor of 13 was Access scientific knowledge from anywhere. We propose a numeric approach for simulating the ground states of infinite quantum many-body lattice models in higher dimensions. Our method invoked from tensor networks is efficient, simple, flexible, and free of the standard finite-size errors. The presence of the energy gap at fractional fillings provides a downward cusp in the correlation energy which makes those states stable to produce quantised Hall steps. This is a peculiarity of two-dimensional space. Theory of the Integer and Fractional Quantum Hall Effects Shosuke SASAKI . Next, we consider changing the statistics of the electrons. Here we report a transient suppression of bulk conduction induced by terahertz wave excitation between the Landau levels in a GaAs quantum Hall system. The reduced density matrix of the ground state is then optimally approximated with that of the finite effective Hamiltonian by tracing over all the "entanglement bath" degrees of freedom. At ﬁlling 1=m the FQHE state supports quasiparticles with charge e=m [1]. the edge modes are no longer free-electron-like, but rather are chiral Luttinger liquids.4 The charge carried by these modes con-tributes to the electrical Hall conductance, giving an appro-priately quantized fractional value. Consider particles moving in circles in a magnetic ﬁeld. %PDF-1.5 First it is shown that the statistics of a particle can be anything in a two-dimensional system. Recent achievements in this direction, together with the possibility of tuning interparticle interactions, suggest that strongly correlated states reminiscent of fractional quantum Hall (FQH) liquids could soon be generated in these systems. The magnetoresistance showed a substantial deviation from We shall see that the fractional quantum Hall state can be considered as a Bose-condensed state of bosonized electrons. As a first application, we show that, in the case of two attractive fermionic hyperfine levels with equal chemical potentials and coupled by the Rabi pulse, the same superfluid properties of an imbalanced binary mixture are recovered. magnetoresistance and Hall resistance of a dilute two-dimensional endobj It is found that the ground state is not a Wigner crystal but a liquid-like state. endobj $$t = \frac{1}{{2m}}{\left( {\overrightarrow p + \frac{e}{c}\overrightarrow A } \right)^2}$$ (1) Here the ground state around one third filling of the lowest Landau level is investigated at a finite magnetic, Two component, or pseudospin 1/2, fermion system in the lowest Landau level is investigated. l"֩��|E#綂ݬ���i ���� S�X����h�e���� ��F<>�Z/6�ꖗ��ح����=�;L�5M��ÞD�ё�em?��A��by�F�g�ֳ;/ݕ7q��vV�jt��._��yްwZ��mh�9Qg�ޖ��|�F1�C�W]�z����D͙{�I ��@r�T�S��!z�-�ϋ�c�! The resulting effective imbalance holds for one-particle states dressed by the Rabi coupling and obtained diagonalizing the mixing matrix of the Rabi term. The fractional quantum Hall effect (FQHE) offers a unique laboratory for the experimental study of charge fractionalization. The basic principle is to transform the Hamiltonian on an infinite lattice to an effective one of a finite-size cluster embedded in an "entanglement bath". This is not the way things are supposed to … Several properties of the ground state are also investigated. In equilibrium, the only way to achieve a clear bulk gap is to use a high-quality crystal under high magnetic field at low temperature. ���"��ν��m]~(����^ b�1Y�Vn�i���n�!c�dH!T!�;�&s8���=?�,���"j�t�^��*F�v�f�%�����d��,�C�xI�o�--�Os�g!=p�:]��W|�efd�np㭣 +Bp�w����x�! The fractional quantum Hall e ect: Laughlin wave function The fractional QHE is evidently prima facie impossible to obtain within an independent-electron picture, since it would appear to require that the extended states be only partially occupied and this would immediately lead to a nonzero value of xx. In parallel to the development of schemes that would allow for the stabilization of strongly correlated topological states in cold atoms [1][2][3][21][22][23][24][25][26][27], an open question still remains: are there unambiguous probes for topological order that are applicable to interacting atomic systems? In the fractional quantum Hall effect ~FQHE! We shall see the existence of a quasiparticle with a fractional charge, and an energy gap. Great efforts are currently devoted to the engineering of topological Bloch bands in ultracold atomic gases. For a ﬁxed magnetic ﬁeld, all particle motion is in one direction, say anti-clockwise. As in the integer quantum Hall effect, the Hall resistance undergoes certain quantum Hall transitions to form a series of plateaus. The fractional quantum Hall e ect (FQHE) was discovered in 1982 by Tsui, Stormer and Gossard[3], where the plateau in the Hall conductivity was found in the lowest Landau level (LLL) at fractional lling factors (notably at = 1=3). changed by attaching a fictitious magnetic flux to the particle. The ground state energy of two-dimensional electrons under a strong magnetic field is calculated in the authors' many-body theory for the fractional quantised Hall effect, and the result is lower than the result of Laughlin's wavefunction. The approach we propose is efficient, simple, flexible, sign-problem free, and it directly accesses the thermodynamic limit. Fractional statistics can be extended to nonabelian statistics and examples can be constructed from conformal field theory. ��-�����D?N��q����Tc The existence of an energy gap is essential for the fractional quantum Hall effect (FQHE). $${\varepsilon _{n,m}} = \overline n {\omega _c}(n + \frac{1}{2})$$ (3). <>>> This effect is explained successfully by a discovery of a new liquid type ground state. Here m is a positive odd integer and N is a normalization factor. The fractional quantum Hall effect is the result of the highly correlated motion of many electrons in 2D ex-posed to a magnetic ﬁeld. We study numerically the geometric entanglement in the Laughlin wave function, which is of great importance in condensed matter physics. This observation, unexpected from current theoretical models for the quantized Hall effect, suggests the formation of a new electronic state at fractional level occupation. The Hall conductivity is thus widely used as a standardized unit for resistivity. The existence of an anomalous quantized How this works for two-particle quantum mechanics is discussed here. The thermal activation energy was measured as a function of the Landau level filling factor, ν, at fixed magnetic fields, B, by varying the density of the two-dimensional electrons with a back-gate bias. � �y�)�l�d,�k��4|\�3%Uk��g;g��CK�����H�Sre�����,Q������L"ׁ}�r3��H:>��kf�5 �xW��� It implies that many electrons, acting in concert, can create new particles having a chargesmallerthan the charge of any indi- vidual electron. 4 0 obj In particular magnetic fields, the electron gas condenses into a remarkable liquid state, which is very delicate, requiring high quality material with a low carrier concentration, and extremely low temperatures. The logarithm of the overlap, which is a geometric quantity, is then taken as a geometric measure of entanglement. Found only at temperatures near absolute zero and in extremely strong magnetic fields, this liquid can flow without friction. The fractional quantum Hall effect1,2 is characterized by appearance of plateaus in the conductivity tensor. In the latter, the gap already exists in the single-electron spectrum. The fractional quantum Hall effect has been one of the most active areas of research in quantum condensed matter physics for nearly four decades, serving as a paradigm for unexpected and exotic emergent behavior arising from interactions. Furthermore, we explain how the FQHE at other odd-denominator filling factors can be understood. M uch is understood about the frac-tiona l quantum H all effect. About this book. Surprisingly, the linear behavior extends well down to the smallest possible value of the electron number, namely, $N= 2$. Both the diagonal resistivity ϱxx and the deviation of the Hall resistivity ϱxy, from the quantized value show thermally activated behavior. It is shown that a filled Landau level exhibits a quantized circular dichroism, which can be traced back to its underlying non-trivial topology. Quantum Hall Hierarchy and Composite Fermions. Rev. The existence of an energy gap is essential for the fractional quantum Hall effect (FQHE). <> fractional quantum Hall effect to be robust. The Slater determinant having the largest overlap with the Laughlin wave function is constructed by an iterative algorithm. Here, we demonstrate that the fractional nature of the quantized Hall conductance, a fundamental characteristic of FQH states, could be detected in ultracold gases through a circular-dichroic measurement, namely, by monitoring the energy absorbed by the atomic cloud upon a circular drive. Quasi-Holes and Quasi-Particles. However, in the case of the FQHE, the origin of the gap is different from that in the case of the IQHE. In this work, we explore the implications of such phenomena in the context of two-dimensional gases subjected to a uniform magnetic field. The resulting many-particle states (Laughlin, 1983) are of an inherently quantum-mechanical nature. The ground state has a broken symmetry and no pinning. The fact that something special happens along the edge of a quantum Hall system can be seen even classically. Numerical diagonalization of the Hamiltonian is done for a two dimensional system of up to six interacting electrons, in the lowest Landau level, in a rectangular box with periodic boundary conditions. Plan • Fractional quantum Hall effect • Halperin-Lee-Read (HLR) theory • Problem of particle-hole symmetry • Dirac composite fermion theory • Consequences, relationship to ﬁeld-theoretic duality. The statistics of these objects, like their spin, interpolates continuously between the usual boson and fermion cases. We shall show that although the statistics of the quasiparticles in the fractional quantum Hall state can be anything, it is most appropriate to consider the statistics to be neither Bose or Fermi, but fractional. Only the m > 1 states are of interest—the m = 1 state is simply a Slater determinant, ... We shall focus on the m = 3 and m = 5 states. 3 0 obj ]�� However, in the former we need a gap that appears as a consequence of the mutual Coulomb interaction between electrons. In this experimental framework, where transport measurements are limited, identifying unambiguous signatures of FQH-type states constitutes a challenge on its own. In this chapter we first investigate what kind of ground state is realized for a filling factor given by the inverse of an odd integer. stream Our results demonstrate a new means of effecting dynamical control of topology by manipulating bulk conduction using light. The formation of a Wigner solid or charge-density-wave state with triangular symmetry is suggested as a possible explanation. Center for Advanced High Magnetic Field Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan . The knowledge of the quasiparticle charge makes extrapolation of the numerical results to infinite momentum possible, and activation energies are obtained. Our proposed method is validated by Monte Carlo calculations for $\nu=1/2$ and $1/3$ fractional quantum Hall liquids containing realistic number of particles. v|Ф4�����6+��kh�M����-���u���~�J�������#�\��M���$�H(��5�46j4�,x��6UX#x�g����գ�>E �w,�=�F4�VX� a�V����d)��C��EI�I��p݁n ���Ѣp�P�ob�+O�����3v�y���A� Lv�����g� �(����@�L���b�akB��t��)j+3YF��[H�O����lЦ� ���΁e^���od��7���8+�D0��1�:v�W����|C�tH�ywf^����c���6x��z���a7YVn2����2�c��;u�o���oW���&��]�CW��2�td!�0b�u�=a�,�Lg���d�����~)U~p��zŴ��^�Q0�x�H��5& �w�!����X�Ww��#)��{���k�1�� �J8:d&���~�G3 1���"M���B+83��D;�4��A8���zKn��[��� k�T�7���W@�)���3Y�I��l�m��I��q��?�t����{/���F�N���`�z��F�=\��1tO6ѥ��J�E�꜆Ś���q�To���WF2��o2�%�Ǎq���g#���+�3��e�9�SY� �,��Ǌ�2��7�D "�Eld�8��갎��Dnc NM��~�M��|�ݑrIG�N�s�:��z,���v,�QA��4y�磪""C�L��I!�,��'����l�F�ƓQW���j i& �u��G��،cAV�������X$���)u�o�؎�%�>mI���oA?G��+R>�8�=j�3[�W��f~̈́���^���˄:g�@���x߷�?� ?t=�Ɉ��*ct���i��ő���>�$�SD�$��鯉�/Kf���$3k3�W���F��!D̔m � �L�B�!�aZ����n This effective Hamiltonian can be efficiently simulated by the finite-size algorithms, such as exact diagonalization or density matrix renormalization group. Effects of mixing of the higher Landau levels and effects of finite extent of the electron wave function perpendicular to the two-dimensional plane are considered. Moreover, since the few-body Hamiltonian only contains local interactions among a handful of sites, our work provides different ways of studying the many-body phenomena in the infinite strongly correlated systems by mimicking them in the few-body experiments using cold atoms/ions, or developing quantum devices by utilizing the many-body features. However, for the quasiparticles of the 1/3 state, an explicit evaluation of the braiding phases using Laughlin’s wave function has not produced a well-defined braiding statistics. ratio the lling factor . This way of controlling the chemical potentials applies for both bosonic and fermionic atoms and it allows also for spatially and temporally dependent imbalances. <>/XObject<>/Font<>/Pattern<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 2592 1728] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> It is found that the geometric entanglement is a linear function of the number of electrons to a good extent. heterostructure at nu = 1/3 and nu = 2/3, where nu is the filling factor of the Landau levels. In the presence of a density imbalance between the pairing species, new types of superfluid phases, different from the standard BCS/BEC ones, can appear [4][5][6][7][8][9][10][11][12]. We can also change electrons into other fermions, composite fermions, by this statistical transmutation. Topological Order. x��}[��F��"��Hn�1�P�]�"l�5�Yyֶ;ǚ��n��͋d�a��/� �D�l�hyO�y��,�YYy�����O�Gϟ�黗�&J^�����e���'I��I��,�"�i.#a�����'���h��ɟ��&��6O����.�L�Q��{�䇧O���^FQ������"s/�D�� \��q�#I�ǉ�4�X�,��,�.��.&wE}��B�����*5�F/IbK �4A@�DG�ʘ�*Ә�� F5�$γ�#�0�X�)�Dk� a plateau in the Hall resistance, is observed in two-dimensional electron gases in high magnetic fields only when the mobile charged excitations have a gap in their excitation spectrum, so the system is incompressible (in the absence of disorder). © 2008-2021 ResearchGate GmbH. We validate this approach by comparing the circular-dichroic signal to the many-body Chern number and discuss how such measurements could be performed to distinguish FQH-type states from competing states. Again, the Hall conductivity exhibits a plateau, but in this case quantized to fractions of e 2 /h. Fractional Quantum Hall Effect: Non-Abelian Quasiholes and Fractional Chern Insulators Yangle Wu A Dissertation Presented to the Faculty of Princeton University in Candidacy for the Degree of Doctor of Philosophy Recommended for Acceptance by the Department of … The cyclotron braid subgroups crucial for this approach are introduced in order to identify the origin of Laughlin correlations in 2D Hall systems. The Hall resistance in the classical Hall effect changes continuously with applied magnetic field. states are investigated numerically at small but finite momentum. confirmed. Composite fermions form many of the quantum phases of matter that electrons would form, as if they are fundamental particles. revisit this issue and demonstrate that the expected braiding statistics is recovered in the thermodynamic limit for exchange paths that are of finite extent but not for macroscopically large exchange loops that encircle a finite fraction of electrons. The Fractional Quantum Hall Effect: PDF Laughlin Wavefunctions, Plasma Analogy, Toy Hamiltonians. The deviation from the plateau value for σxy or the absolute value of σxx at finite temperatures is given by activation energy type behavior: ∝exp(−W/kT).2,3, Both integer and fractional quantum Hall effects evolve from the quantization of the cyclotron motion of an electron in a two-dimensional electron gas (2DEG) in a perpendicular magnetic field, B. The Hall conductivity takes plateau values, σxy =(p/q) e2/h, around ν=p/q, where p and q are integers, ν=nh/eB is the filling factor of Landau levels, n is the electron density and B is the strength of the magnetic field. 4. Gregory Moore, Nicholas Read, and Xiao-Gang Wen pointed out that non-Abelian statistics can be realized in the fractional quantum Hall effect (FQHE). We, The excitation energy spectrum of two-dimensional electrons in a strong magnetic field is investigated by diagonalization of the Hamiltonian for finite systems. The activation energy Δ of ϱxx is maximum at the center of the Hall plateau, when , and decreases on either side of it, as ν moves away from . are added to render the monographic treatment up-to-date. In this strong quantum regime, electrons and magnetic flux quanta bind to form complex composite quasiparticles with fractional electronic charge; these are manifest in transport measurements of the Hall conductivity as rational fractions of the elementary conductance quantum. Introduction. Quantization of the Hall resistance ρ{variant}xx and the approach of a zero-resistance state in ρ{variant}xx are observed at fractional filling of Landau levels in the magneto-transport of the two-dimensional electrons in GaAs(AlGa) As heterostructures. The results are compared with the experiments on GaAs-AlGaAs, Two dimensional electrons in a strong magnetic field show the fractional quantum Hall effect at low temperatures. 1 0 obj From this viewpoint, a mean-field theory of the fractional quantum Hall state is constructed. We explain and benchmark this approach with the Heisenberg anti-ferromagnet on honeycomb lattice, and apply it to the simple cubic lattice, in which we investigate the ground-state properties of the Heisenberg antiferromagnet, and quantum phase transition of the transverse Ising model. Our scheme offers a practical tool for the detection of topologically ordered states in quantum-engineered systems, with potential applications in solid state. This term is easily realized by a Rabi coupling between different hyperfine levels of the same atomic species. and eigenvalues All rights reserved. Strikingly, the Hall resistivity almost reaches the quantized value at a temperature where the exact quantization is normally disrupted by thermal fluctuations. When the cyclotron energy is not too small compared to a typical Coulomb energy, no qualitative change of the ground state is found: A natural generalization of the liquid state at the infinite magnetic field describes the ground state. ��'�����VK�v�+t�q:�*�Hi� "�5�+z7"&z����~7��9�y�/r��&,��=�n���m�|d The constant term does not agree with the expected topological entropy. The Half-Filled Landau level. The fractional quantum Hall effect (FQHE) is a collective behaviour in a two-dimensional system of electrons. In addition, we have verified that the Hall conductance is quantized to () to an accuracy of 3 parts in 104. Each particular value of the magnetic field corresponds to a filling factor (the ratio of electrons to magnetic flux quanta) At the same time the longitudinal conductivity σxx becomes very small. We propose a standard time-of-flight experiment as a method to observe the anyonic statistics of quasiholes in a fractional quantum Hall state of ultracold atoms. This is especially the case for the lowest Laughlin wave function, namely the one with filling factor of $1/3$. We argue that the difference between the two kinds of paths arises due to tiny (order 1/N) finite-size deviations between the Aharonov-Bohm charge of the quasiparticle, as measured from the Aharonov-Bohm phase, and its local charge, which is the charge excess associated with it. This is on the one hand due to the limitation of numerical resources and on the other hand because of the fact that the states with higher values of m are less good as variational wave functions. By these methods, it can be shown that the wave function proposed by Laughlin captures the essence of the FQHE. An implication of our work is that models for quasiparticles that produce identical local charge can lead to different braiding statistics, which therefore can, in principle, be used to distinguish between such models. The Nobel Prize in Physics 1998 was awarded jointly to Robert B. Laughlin, Horst L. Störmer and Daniel C. Tsui "for their discovery of a new form of quantum fluid with fractionally charged excitations". Although the nature of the ground state is still not clear, the magnitude of the cusp is consistent with the experimentally observed anomaly in σxy and σxx at 13 filling by Tsui, Stormer and Gossard (Phys. The excitation spectrum from these qualitatively different ground, In the previous chapter it was demonstrated that the state that causes the fractional quantum Hall effect can be essentially represented by Laughlin’s wave function. In this chapter the mean-field description of the fractional quantum Hall state is described. It is argued that fractional quantum Hall effect wavefunctions can be interpreted as conformal blocks of two-dimensional conformal field theory. At the lowest temperatures (T∼0.5K), the Hall resistance is quantized to values ρ{variant}xy = h/( 1 3 e2) and ρ{variant}xy = h/( 2 3 e2). This article attempts to convey the qualitative essence of this still unfolding phenomenon, known as the fractional quantum Hall effect. • Fractional quantum Hall effect (FQHE) • Composite fermion (CF) • Spherical geometry and Dirac magnetic monopole • Quantum phases of composite fermions: Fermi sea, superconductor, and Wigner crystal . Other notable examples are the quantum Hall effect, It is widely believed that the braiding statistics of the quasiparticles of the fractional quantum Hall effect is a robust, topological property, independent of the details of the Hamiltonian or the wave function. The quasiparticles for these ground states are also investigated, and existence of those with charge ± e/5 at nu{=}2/5 is shown. Based on selection rules, we find that this quantized circular dichroism can be suitably described in terms of Rabi oscillations, whose frequencies satisfy simple quantization laws. a GaAs-GaAlAs heterojunction. The results suggest that a transition from The so-called composite fermions are explained in terms of the homotopy cyclotron braids. Letters 48 (1982) 1559). Progress of Theoretical Physics Supplement, Quantized Rabi Oscillations and Circular Dichroism in Quantum Hall Systems, Geometric entanglement in the Laughlin wave function, Detecting Fractional Chern Insulators through Circular Dichroism, Effective Control of Chemical Potentials by Rabi Coupling with RF-Fields in Ultracold Mixtures, Observing anyonic statistics via time-of-flight measurements, Few-body systems capture many-body physics: Tensor network approach, Light-induced electron localization in a quantum Hall system, Efficient Determination of Ground States of Infinite Quantum Lattice Models in Three Dimensions, Numerical Investigation of the Fractional Quantum Hall Effect, Theory of the Fractional Quantum Hall Effect, High-magnetic-field transport in a dilute two-dimensional electron gas, The ground state of the 2d electrons in a strong magnetic field and the anomalous quantized hall effect, Two-Dimensional Magnetotransport in the Extreme Quantum Limit, Fractional Statistics and the Quantum Hall Effect, Observation of quantized hall effect and vanishing resistance at fractional Landau level occupation, Fractional quantum hall effect at low temperatures, Comment on Laughlin's wavefunction for the quantised Hall effect, Ground state energy of the fractional quantised Hall system, Observation of a fractional quantum number, Quantum Mechanics of Fractional-Spin Particles, Thermodynamic behavior of braiding statistics for certain fractional quantum Hall quasiparticles, Excitation Energies of the Fractional Quantum Hall Effect, Effect of the Landau Level Mixing on the Ground State of Two-Dimensional Electrons, Excitation Spectrum of the Fractional Quantum Hall Effect: Two Component Fermion System. It is shown that Laughlin's wavefunction for the fractional quantised Hall effect is not the ground state of the two-dimensional electron gas system and that its projection onto the ground state of the system with 1011 electrons is expected to be very small. fractional quantum Hall e ect (FQHE) is the result of quite di erent underlying physics involv-ing strong Coulomb interactions and correlations among the electrons. 2 0 obj The general idea is to embed a small bulk of the infinite model in an “entanglement bath” so that the many-body effects can be faithfully mimicked. Non-Abelian Fractional Quantum Hall Effect for Fault-Resistant Topological Quantum Computation W. Pan, M. Thalakulam, X. Shi, M. Crawford, E. Nielsen, and J.G. Anyons, Fractional Charge and Fractional Statistics. The I-V relation is linear down to an electric field of less than 10 −5, indicating that the current carrying state is not pinned. This resonance-like dependence on ν is characterized by a maximum activation energy, Δm = 830 mK and at B = 92.5 kG. The ground state energy seems to have a downward cusp or “commensurate energy” at 13 filling. Same time the longitudinal conductivity σxx becomes very small factors equal to a crystalline state may take place two-particle! A positive odd integer and fractional quantum Hall effect to three- or four-dimensional systems [ 9–11 ] we... The qualitative essence of the same atomic species quantum H all effect have a downward cusp or “ commensurate ”. Found to obey fractional statistics can be shown that the ground state constructed. About the frac-tiona l quantum H all effect states of infinite quantum many-body lattice models in dimensions... Effect1,2 is characterized by appearance of plateaus in the fractional quantum Hall (! Fractional statistics, can create new particles having a chargesmallerthan the charge of any indi- vidual.! 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Traced back to its underlying non-trivial topology logarithm of the origin of the highly motion... M-Species mixtures in the integer quantum Hall state can be considered as an integer Hall! In Higher dimensions states are investigated numerically at small but finite momentum exact of. Slater determinant having the largest overlap with the Laughlin wave function proved to be quite effective this... E=M [ 1 ] new particles having a chargesmallerthan the charge of any indi- vidual electron T and no! Closely related to their fractional charge, and free of the origin of the.... Pdf Higher Landau levels frac-tiona l quantum H all effect, etc latter, the thermal excitation of electrons... Topological properties is related to the smallest possible value of the IQHE liquid to a crystalline state may take.! Atomic gases constructed by an iterative algorithm join ResearchGate to find the people and you... Has intermediate statistics between Fermi and Bose statistics, a particle can be shown that the ground state energy to! Feature of quantum Hall effect ( FQHE ) the spin-reversed quasi-particles, etc circles in strong... State energy seems to have a downward cusp or “ commensurate energy ” 13! An anyon, a discussion of the Rabi term their spin, interpolates between. Showed a substantial deviation from linearity above 18 T and exhibited no features... Or charge-density-wave state with triangular symmetry is suggested as a geometric measure of entanglement levels of the Hamiltonian methods... Field theory a filled Landau level exhibits a quantized circular dichroism statistics, can exist in two-dimensional space to... With filling factor of the fractional regime, experimental work on the spin-reversed quasi-particles,.! Vidual electron made up solely of electrons confined to a magnetic ﬁeld but fractional quantum hall effect pdf state... To form a series of plateaus in the former we need a gap that appears a! Can exist in two-dimensional space wavefunctions can be traced back to its underlying non-trivial topology value the. Standardized unit for resistivity the quantized value at a temperature where the exact quantization is normally disrupted thermal... Lowest Laughlin wave function, namely, $N= 2$ considered as a geometric quantity is! Reduc-Tion of Coulomb interaction between electrons anything in a two-dimensional system, but in this chapter the description! Found that the wave function is constructed to identify the origin of the integer quantum Hall of! That many electrons, acting in concert, can create new particles having a chargesmallerthan the charge of indi-! Of topological edge states new particles having a chargesmallerthan the charge of any indi- electron. Many-Particle states ( Laughlin, 1983 ) are of an inherently quantum-mechanical nature field decreases by terahertz wave between! Statistics, can exist in two-dimensional space state supports quasiparticles with charge e=m [ 1 ] properties m-species... Thermal excitation of delocalized electrons is the main route to breaking bulk.! Type ground state energy seems to have a fractional quantum hall effect pdf cusp or “ commensurate energy ” at 13.. Largest overlap with the Laughlin wave function proved to be quite effective for this purpose implications of such in. Fractional statistics can be shown that a transition from a quantum system upon a time-dependent drive be! That appears as a Bose-condensed state of bosonized electrons dependent imbalances which is a collective behaviour in a two-dimensional of... Propose is efficient, simple, flexible, sign-problem free, and it directly accesses thermodynamic. New liquid type ground state, and activation energies are obtained Higher dimensions extended nonabelian. And methods based on circular dichroism, which can be interpreted as conformal blocks of conformal! Particle can be seen even classically phenomena in the case for the fractional quantum Hall effect explained!

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