SOME FRACTIONS ARE MORE SPECIAL THAN OTHERS: NEWS FROM THE FRACTIONAL QUANTUM HALL ZONE

2002 ◽  
Vol 16 (20n22) ◽  
pp. 2940-2945 ◽  
Author(s):  
W. PAN ◽  
H. L. STORMER ◽  
D. C. TSUI ◽  
L. N. PFEIFFER ◽  
K. W. BALDWIN ◽  
...  

We report observation of new fractions: 4/11, 5/13, and 6/17 between ν=2/5 and ν=1/3, 4/3 and 5/17 between ν=1/3 and ν=2/7, and 4/19 between ν=2/9 and ν=1/5. The ν=4/11 state was studied in detail. The tilting magnetic field data show that its ground state is spin-polarized.

2004 ◽  
Vol 18 (27n29) ◽  
pp. 3871-3874 ◽  
Author(s):  
KAREL VÝBORNÝ ◽  
DANIELA PFANNKUCHE

Transitions between spin polarized and spin singlet incompressible ground state of quantum Hall systems at filling factor 2/3 are studied by means of exact diagonalization with eight electrons. We observe a stable exactly half–polarized state becoming the absolute ground state around the transition point. This might be a candidate for the anomaly observed during the transition in optical experiments. The state reacts strongly to magnetic inhomogeneities but it prefers stripe–like spin structures to formation of domains.


1991 ◽  
Vol 05 (10) ◽  
pp. 1725-1729
Author(s):  
F. C. Zhang ◽  
M. Ma

Ideal anyons with statistics ν in a strong magnetic field are studied by means of a similarity transformation. The ground state exhibits "integer" quantum Hall effect at filling factor 1/ν with quasiparticle excitations of charge q/ν and statistics -1/ν. Certain electron FQH states can be considered as realization of this, for example, the sequence 2/5, 3/7, … hierarchy of the 1/3 state. This may explain the observed quasiparticle-quasihole asymmetry in the fractional quantum Hall hierarchy.


1991 ◽  
Vol 05 (19) ◽  
pp. 1293-1299 ◽  
Author(s):  
CHRISTOPHER TING ◽  
C. H. LAI

We discuss Laughlin's ground state and its derivation in the path integral approach. When the external magnetic field is very strong, we regard all electron-electron interactions such as the Coulomb term as weak perturbations. It seems that from the non-trivial topology of the configuration space alone, it is possible to arrive at a Hamiltonian for which Laughlin wavefunctions are exact ground states.


2011 ◽  
Vol 106 (23) ◽  
Author(s):  
Titus Neupert ◽  
Luiz Santos ◽  
Claudio Chamon ◽  
Christopher Mudry

2021 ◽  
Vol 10 (4) ◽  
Author(s):  
Ajit Coimbatore Balram

Fascinating structures have arisen from the study of the fractional quantum Hall effect (FQHE) at the even denominator fraction of 5/25/2. We consider the FQHE at another even denominator fraction, namely \nu=2+3/8ν=2+3/8, where a well-developed and quantized Hall plateau has been observed in experiments. We examine the non-Abelian state described by the ``\bar{3}\bar{2}^{2}1^{4}3‾2‾214" parton wave function and numerically demonstrate it to be a feasible candidate for the ground state at \nu=2+3/8ν=2+3/8. We make predictions for experimentally measurable properties of the \bar{3}\bar{2}^{2}1^{4}3‾2‾214 state that can reveal its underlying topological structure.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tsuneya Yoshida ◽  
Koji Kudo ◽  
Yasuhiro Hatsugai

AbstractWe demonstrate the emergence of a topological ordered phase for non-Hermitian systems. Specifically, we elucidate that systems with non-Hermitian two-body interactions show a fractional quantum Hall (FQH) state. The non-Hermitian Hamiltonian is considered to be relevant to cold atoms with dissipation. We conclude the emergence of the non-Hermitian FQH state by the presence of the topological degeneracy and by the many-body Chern number for the ground state multiplet showing Ctot = 1. The robust topological degeneracy against non-Hermiticity arises from the manybody translational symmetry. Furthermore, we discover that the FQH state emerges without any repulsive interactions, which is attributed to a phenomenon reminiscent of the continuous quantum Zeno effect.


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