One of my favorite times in the academic year occurs in early spring when I give my class of
extremely bright graduate students, who have mastered quantum mechanics but are …

A review of the quantised Hall effect is given. The author surveys experiments and theories
on the normal and fractional quantum Hall effect including recent developments. As a …

An even-denominator rational quantum number has been observed in the Hall resistance of
a two-dimensional electron system. At partial filling of the second Landau level ν= 2+(1/2 …

We present a theory of the collective excitation spectrum in the fractional quantum Hall effect
which is closely analogous to Feynman's theory of superfluid helium. The predicted …

The quantum Hall effect (QHE) provides an invariant reference for resistance linked to
natural constants. It is used worldwide to maintain and compare the unit of resistance. The …

We report ultralow temperature experiments on the obscure fractional quantum Hall effect at
Landau level filling factor ν= 5/2 in a very high-mobility specimen of μ= 1.7× 10 7 cm 2/V s …

The case is made that the spin-liquid state of a Mott insulator, hypothesized to exist by
Anderson and identified by him as the correct context for discussing high-temperature …

Following the past seventeen-year developmental path in the research of semiconductor
superlattices and quantum wells, significant milestones are presented with emphasis on …

A long wavelength, low-energy excitation of the fractional quantum Hall state at ν= 1/3 has
been observed by inelastic light scattering. The mode appears as a very sharp peak with …

We observe a novel transition between distinct fractional quantum Hall states sharing the
same filling fraction ν=(8/5. The transition is driven by tilting the two-dimensional electron …