11 research outputs found
Interacting SUSY-singlet matter in non-relativistic Chern-Simons theory
We construct an example of supersymmetric Chern-Simons-matter theory with a
matter field transforming as a singlet representation of the supersymmetry
algebra, where the bosonic and fermionic degrees of freedom do not match. This
is obtained as a non-relativistic limit of the N=2 Chern-Simons-matter theory
in 1+2 dimensions, where the particle and anti-particle coexist. We also study
the index to investigate the mimatch of bosonic and fermionic degrees of
freedom.Comment: 11page
Quantum criticality and black holes
Many condensed matter experiments explore the finite temperature dynamics of
systems near quantum critical points. Often, there are no well-defined
quasiparticle excitations, and so quantum kinetic equations do not describe the
transport properties completely. The theory shows that the transport
co-efficients are not proportional to a mean free scattering time (as is the
case in the Boltzmann theory of quasiparticles), but are completely determined
by the absolute temperature and by equilibrium thermodynamic observables.
Recently, explicit solutions of this quantum critical dynamics have become
possible via the AdS/CFT duality discovered in string theory. This shows that
the quantum critical theory provides a holographic description of the quantum
theory of black holes in a negatively curved anti-de Sitter space, and relates
its transport co-efficients to properties of the Hawking radiation from the
black hole. We review how insights from this connection have led to new results
for experimental systems: (i) the vicinity of the superfluid-insulator
transition in the presence of an applied magnetic field, and its possible
application to measurements of the Nernst effect in the cuprates, (ii) the
magnetohydrodynamics of the plasma of Dirac electrons in graphene and the
prediction of a hydrodynamic cyclotron resonance.Comment: 12 pages, 2 figures; Talk at LT25, Amsterda
A tunneling picture of dual giant Wilson loop
We further discuss a rotating dual giant Wilson loop (D3-brane) solution
constructed in Lorentzian AdS by Drukker et al. The solution is shown to be
composed of a dual giant Wilson loop and a dual giant graviton by minutely
examining its shape. This observation suggests that the corresponding
gauge-theory operator should be a k-th symmetric Wilson loop with the
insertions of dual giant graviton operators. To support the correspondence, the
classical action of the solution should be computed and compared with the
gauge-theory result. For this purpose we first perform a Wick rotation to the
Lorentzian solution by following the tunneling prescription and obtain
Euclidean solutions corresponding to a circular or a straight-line Wilson loop.
In Euclidean signature boundary terms can be properly considered in the
standard manner and the classical action for the Euclidean solutions can be
evaluated. The result indeed reproduces the expectation value of the k-th
symmetric Wilson loop as well as the power-law behavior of the correlation
function of dual giant graviton operators.Comment: 34 pages, 19 figures, v2: references adde
A family of super Schrodinger invariant Chern-Simons matter systems
We investigate non-relativistic limits of the N=3 Chern-Simons matter system
in 1+2 dimensions. The relativistic theory can generate several inequivalent
super Schodinger invariant theories, depending on the degrees of freedom we
choose to retain in the non-relativistic limit. The maximally supersymmetric
Schrodinger invariant theory is obtained by keeping all particle degrees of
freedom. The other descendants, where particles and anti-particles coexist, are
also Schrodinger invariant but preserve less supersymmetries. Thus, we have a
family of super Schrodinger invariant field theories produced from the parent
relativistic theory.Comment: 1+35 pages, references added and typos fixe
Instabilities of Black Strings and Branes
We review recent progress on the instabilities of black strings and branes
both for pure Einstein gravity as well as supergravity theories which are
relevant for string theory. We focus mainly on Gregory-Laflamme instabilities.
In the first part of the review we provide a detailed discussion of the
classical gravitational instability of the neutral uniform black string in
higher dimensional gravity. The uniform black string is part of a larger phase
diagram of Kaluza-Klein black holes which will be discussed thoroughly. This
phase diagram exhibits many interesting features including new phases,
non-uniqueness and horizon-topology changing transitions. In the second part,
we turn to charged black branes in supergravity and show how the
Gregory-Laflamme instability of the neutral black string implies via a
boost/U-duality map similar instabilities for non- and near-extremal smeared
branes in string theory. We also comment on instabilities of D-brane bound
states. The connection between classical and thermodynamic stability, known as
the correlated stability conjecture, is also reviewed and illustrated with
examples. Finally, we examine the holographic implications of the
Gregory-Laflamme instability for a number of non-gravitational theories
including Yang-Mills theories and Little String Theory.Comment: 119 pages, 16 figures. Invited review for Classical and Quantum
Gravit
Universal -linear resistivity and Planckian dissipation in overdoped cuprates
International audienceThe perfectly linear temperature dependence of the electrical resistivity observed as Tâ0 in a variety of metals close to a quantum critical point is a major puzzle of condensed-matter physics . Here we show that T-linear resistivity as T0 is a generic property of cuprates, associated with a universal scattering rate. We measured the low-temperature resistivity of the bilayer cuprate BiSrCaCuO and found that it exhibits a T-linear dependence with the same slope as in the single-layer cuprates BiSrCuO , LaNdSrCuO and LaSrCuO , despite their very different Fermi surfaces and structural, superconducting and magnetic properties. We then show that the T-linear coefficient (per CuO plane), A1, is given by the universal relation A1T= , where is the electron charge, is the Planck constant and is the Fermi temperature. This relation, obtained by assuming that the scattering rate 1/ of charge carriers reaches the Planckian limit, whereby /=, works not only for holedoped cuprates but also for electron-doped cuprates, despite the different nature of their quantum critical point and strength of their electron correlations