Abstract:
It is argued that the composite fermion liquid is a promising candidate for an observation of the elusive, interaction driven magnetization first proposed by Bloch seven decades ago. In analogy to what is theoretically believed to be the case for the idealized electron gas in zero magnetic field, this spontaneously broken symmetry phase is predicted to occur prior to a transition into the Wigner crystal.

Abstract:
We consider the effect of interactions on electrons confined to two dimensions at Landau level filling $\nu=2$, with the specific aim to determine the range of parameters where the fully polarized state is stable. We calculate the charge and the spin density collective modes in random phase approximation (RPA) including vertex corrections (also known as time dependent Hartree Fock), and treating the Landau level mixing accurately within the subspace of a single particle hole pair. It is found that the spin wave excitation mode of the fully polarized state has a roton minimum which deepens as a result of the interaction induced Landau level mixing, and the energy of the roton vanishes at a critical Zeeman energy signaling an instability of the fully polarized state at still lower Zeeman energies. The feasibility of the experimental observation of the roton minimum in the spin wave mode and its softening will be discussed. The spin and charge density collective modes of the unpolarized state are also considered, and a phase diagram for the $\nu =2$ state as a function of $r_{S}$ and the Zeeman energy is obtained.

Abstract:
The true nature of the lowest-energy, long-wavelength neutral excitation of the fractional quantum Hall effect has been a long outstanding problem. In this Letter, we establish that it is a two-roton bound state.

Abstract:
There now exists preliminary experimental evidence for some fractions, such as $\nu$ = 4/11 and 5/13, that do not belong to any of the sequences $\nu=n/(2pn\pm 1)$, $p$ and $n$ being integers. We propose that these states are mixed states of composite fermions of different flavors, for example, composite fermions carrying two and four vortices. We also obtain an estimate of the lowest-excitation dispersion curve as well as the transport gap; the gaps for 4/11 are smaller than those for 1/3 by approximately a factor of 50.

Abstract:
A three feet two inch (96 cm) tall achondroplastic patient with urothelial cell carcinoma involving renal pelvis was scheduled for a radical nephrectomy. Radial artery cannulation and central venous access were securedin the pre-induction period. After induction, the airway was secured using a flexible fibreoptic scope. General anaesthesia was maintained with oxygen-nitrous-oxide and continuous propofol infusion. The total duration of anaesthesia was three hours and 50 minutes. To the best of the authors’ knowledge, this is the shortest adult achondroplastic patient ever reported to undergo such major abdominal surgery under general anaesthesia. The anaesthetic implications in patients with achondroplasia are reviewed in this case report.

Abstract:
The eigenstates of interacting electrons in the fractional quantum Hall phase typically form fairly well defined bands in the energy space. We show that the composite fermion theory gives insight into the origin of these bands and provides an accurate and complete microscopic description of the strongly correlated many-body states in the low-energy bands. Thus, somewhat like in Landau's fermi liquid theory, there is a one-to-one correspondence between the low energy Hilbert space of strongly interacting electrons in the fractinal quantum Hall regime and that of weakly interacting electrons in the integer quantum Hall regime.

Abstract:
Motivated by a mean-field approach, which has been employed for anyon superfluidity and the fractional quantum Hall effect, the quantum Hall effect (QHE) of hard-core bosons is investigated. It is shown that QHE is possible {\em only} in the thermodynamic limit. The filling factors where QHE may be expected are obtained with the help of two adiabatic schemes.

Abstract:
We demonstrate the formation of composite fermions in two-dimensional quantum dots under high magnetic fields. The composite fermion interpretation provides a simple way to understand several qualitative and quantitative features of the numerical results obtained earlier in exact diagonalization studies. In particular, the ground states are recognized as compactly filled quasi-Landau levels of composite fermions.

Abstract:
We investigate, using finite size numerical calculations, the spin-polarized fractional quantum Hall effect (FQHE) in the first excited Landau level (LL). We find evidence for the existence of an incompressible state at $\nu = \frac{7}{3} = 2+\frac{1}{3}$, but not at $\nu = 2+\frac{2}{5}$. Surprisingly, the 7/3 state is found to be strongest at a finite thickness. The structure of the low- lying excited states is found to be markedly different from that in the lowest LL. This study also rules out FQHE at a large number of odd-denominator fractions in the lowest LL.