Publications (81)
A Solvable Spin-Glass of Quantum Rotors
Jinwu Ye, Subir Sachdev, N. Read
We examine a model of -component quantum rotors coupled by Gaussian-distributed random, infinite-range exchange interactions. A complete solution is obtained at in th…
Tensor network trial states for chiral topological phases in two dimensions and a no-go theorem in any dimension
J. Dubail, N. Read
Trial wavefunctions that can be represented by summing over locally-coupled degrees of freedom are called tensor network states (TNSs); they have seemed difficult to construct for…
Enlarged symmetry algebras of spin chains, loop models, and S-matrices
N. Read, H. Saleur
The symmetry algebras of certain families of quantum spin chains are considered in detail. The simplest examples possess m states per site (m\geq2), with nearest-neighbor interacti…
Continuum limit and symmetries of the periodic gl(1|1) spin chain
A. M. Gainutdinov, N. Read, H. Saleur
This paper is the first in a series devoted to the study of logarithmic conformal field theories (LCFT) in the bulk. Building on earlier work in the boundary case, our general stra…
Quantum Hall states and boson triplet condensate for rotating spin-1 bosons
J. W. Reijnders, F. J. M. van Lankvelt, K. Schoutens +1
We propose and analyze two series of clustered quantum Hall states for rotating systems of spin-1 bosons. The first series (labelled SU(4)_k) includes the exact ground states of a…
Spin-Peierls states of quantum antiferromagnets on the lattice
Subir Sachdev, N. Read
We discuss the quantum paramagnetic phases of Heisenberg antiferromagnets on the 1/5-depleted square lattice found in . The possible phases of the quantum dimer model o…
Topological central charge from Berry curvature: gravitational anomalies in trial wavefunctions for topological phases
Barry Bradlyn, N. Read
We show that the topological central charge of a topological phase can be directly accessed from the ground-state wavefunctions for a system on a surface as a Berry curvature produ…
Free expansion of lowest Landau level states of trapped atoms: a wavefunction microscope
N. Read, N. R. Cooper
We show that for any lowest-Landau-level state of a trapped, rotating, interacting Bose gas, the particle distribution in coordinate space in a free expansion (time of flight) expe…
Random-bond Ising model in two dimensions, the Nishimori line, and supersymmetry
Ilya A. Gruzberg, N. Read, Andreas W. W. Ludwig
We consider a classical random-bond Ising model (RBIM) with binary distribution of bonds on the square lattice at finite temperature. In the phase diagram of this model the…
Invariant structure of the hierarchy theory of fractional quantum Hall states with spin
M. Milovanovic, N. Read
We describe the invariant structure common to abelian fractional quantum Hall systems with spin. It appears in a generalization of the lattice description of the polarized hierarch…
Metallic spin glasses
Subir Sachdev, N. Read
Recent work on the zero temperature phases and phase transitions of strongly random electronic system is reviewed. The transition between the spin glass and quantum paramagnet is e…
Incompressible liquid state of rapidly-rotating bosons at filling factor 3/2
E. H. Rezayi, N. Read, N. R. Cooper
Bosons in the lowest Landau level, such as rapidly-rotating cold trapped atoms, are investigated numerically in the specially interesting case in which the filling factor (ratio of…
Fractional quantum Hall effect and nonabelian statistics
N. Read, G. Moore
It is argued that fractional quantum Hall effect wavefunctions can be interpreted as conformal blocks of two-dimensional conformal field theory. Fractional statistics can be extend…
Low-energy effective theory in the bulk for transport in a topological phase
Barry Bradlyn, N. Read
We construct a low-energy effective action for a two-dimensional non-relativistic topological (i.e.\ gapped) phase of matter in a continuum, which completely describes all of its b…
Quasiparticle spin from adiabatic transport in quantum Hall trial wavefunctions
N. Read
Quasiparticle spin (in the spacetime sense) couples to curvature of space. Here this fact is used to calculate the spin of quasiholes in trial quantum Hall states by adiabatically…
Structural analysis of Gibbs states and metastates in short-range classical spin glasses: indecomposable metastates, dynamically-frozen states, and metasymmetry
N. Read
We consider short-range classical spin glasses, or other disordered systems, consisting of Ising spins. For a low-temperature Gibbs state in infinite size in such a system, for giv…
Complexity as information in spin-glass Gibbs states and metastates: upper bounds at nonzero temperature and long-range models
N. Read
In classical finite-range spin systems, especially those with disorder such as spin glasses, a low-temperature Gibbs state may be a mixture of a number of pure or ordered states; t…
Exponents and bounds for uniform spanning trees in d dimensions
N. Read
Uniform spanning trees are a statistical model obtained by taking the set of all spanning trees on a given graph (such as a portion of a cubic lattice in d dimensions), with equal…
Exact spectra of conformal supersymmetric nonlinear sigma models in two dimensions
N. Read, H. Saleur
We study two-dimensional nonlinear sigma models in which the target spaces are the coset supermanifolds U(n+m|n)/[U(1)\times U(n+m-1|n)] \cong CP^{n+m-1|n} (projective superspaces)…
Continuum quantum ferromagnets at finite temperature and the Quantum Hall effect
N. Read, Subir Sachdev
We study finite temperature () properties of the continuum quantum field theory of systems with a ferromagnetic ground state. A scaling theory of the system is discussed c…
Nontrivial maturation metastate-average state in a one-dimensional long-range Ising spin glass: above and below the upper critical range
S. Jensen, N. Read, A. P. Young
Understanding the low-temperature pure state structure of spin glasses remains an open problem in the field of statistical mechanics of disordered systems. Here we study Monte Carl…
Quantum field theory of metallic spin glasses
Subir Sachdev, N. Read, R. Oppermann
We introduce an effective field theory for the vicinity of a zero temperature quantum transition between a metallic spin glass (``spin density glass'') and a metallic quantum param…
Large N expansion for frustrated and doped quantum antiferromagnets
Subir Sachdev, N. Read
A large N expansion technique, based on symplectic (Sp(N)) symmetry, for frustrated magnetic systems is studied. The phase diagram of a square lattice, spin S, quantum antiferromag…
Kubo formulas for viscosity: Hall viscosity, Ward identities, and the relation with conductivity
Barry Bradlyn, Moshe Goldstein, N. Read
We derive from first principles the Kubo formulas for the stress-stress response function at zero wavevector that can be used to define the full complex frequency-dependent viscosi…
Wavefunctions and counting formulas for quasiholes of clustered quantum Hall states on a sphere
N. Read
The quasiholes of the Read-Rezayi clustered quantum Hall states are considered, for any number of particles and quasiholes on a sphere, and for any degree k of clustering. A set of…
Paired fractional quantum Hall states and the nu=5/2 puzzle
N. Read
Work on the problem of the fractional quantum Hall state is reviewed, with emphasis on recent progress concerning paired states.
Lowest-Landau-level theory of the quantum Hall effect: the Fermi-liquid-like state
N. Read
A theory for a Fermi-liquid-like state in a system of charged bosons at filling factor one is developed, working in the lowest Landau level. The approach is based on a representati…
Metastates and Replica Symmetry Breaking
C. M. Newman, N. Read, D. L. Stein
In this review we define and discuss metastates, mathematical tools with general applicability to thermodynamic systems which are particularly useful when working with disordered o…
Entanglement subspaces, trial wavefunctions, and special Hamiltonians in the fractional quantum Hall effect
T. S. Jackson, N. Read, S. H. Simon
We consider spaces of trial wavefunctions for ground states and edge excitations in the fractional quantum Hall effect that can be obtained in various ways. In one way, functions a…
Comment on "Cooper instability of composite fermions"
N. Read
We comment on the recent paper by Scarola, Park, and Jain [Nature v. 406, p. 863 (2000); cond-mat/0012030] on a trial wavefunction calculation of pairing in a fractional quantum Ha…
Proof of single-replica equivalence in short-range spin glasses
C. M. Newman, N. Read, D. L. Stein
We consider short-range Ising spin glasses in equilibrium at infinite system size, and prove that, for fixed bond realization and a given Gibbs state drawn from a suitable metastat…
Entanglement spectra of complex paired superfluids
J. Dubail, N. Read
We study the entanglement in various fully-gapped complex paired states of fermions in two dimensions, focusing on the entanglement spectrum (ES), and using the BCS form of the gro…
Comment on "Galilean invariance at quantum Hall edge"
J. Höller, N. Read
In a recent paper by S. Moroz, C. Hoyos, and L. Radzihovsky [Phys. Rev. B 91, 195409 (2015)], it is claimed that the conductivity at low frequency and small wavevector alo…
Associative algebraic approach to logarithmic CFT in the bulk: the continuum limit of the gl(1|1) periodic spin chain, Howe duality and the interchiral algebra
A. M. Gainutdinov, N. Read, H. Saleur
We develop in this paper the principles of an associative algebraic approach to bulk logarithmic conformal field theories (LCFTs). We concentrate on the closed spin-chain…
Exact exponents for the spin quantum Hall transition
Ilya A. Gruzberg, Andreas W. W. Ludwig, N. Read
We consider the spin quantum Hall transition which may occur in disordered superconductors with unbroken SU(2) spin-rotation symmetry but broken time-reversal symmetry. Using super…
On the practicalities of producing a nuclear weapon using high-assay low-enriched uranium
P. Cosgrove, N. Read
It was recently argued by Kemp et al. that HALEU (high-assay low-enriched uranium, or uranium enriched up to 19.75\%) can conceivably be used to produce a nuclear weapon and on thi…
Non-Abelian spin-singlet quantum Hall states: wave functions and quasihole state counting
E. Ardonne, N. Read, E. Rezayi +1
We investigate a class of non-Abelian spin-singlet (NASS) quantum Hall phases, proposed previously. The trial ground and quasihole excited states are exact eigenstates of certain k…
Non-Abelian quantized Hall states of electrons at filling factors 12/5 and 13/5 in the first excited Landau level
E. H. Rezayi, N. Read
We present results of extensive numerical calculations on the ground state of electrons in the first excited (n=1) Landau level with Coulomb interactions, and including non-zero th…
Radiation-Induced Magnetoresistance Oscillations in a 2D Electron Gas
Adam C. Durst, Subir Sachdev, N. Read +1
Recent measurements of a 2D electron gas subjected to microwave radiation reveal a magnetoresistance with an oscillatory dependence on the ratio of radiation frequency to cyclotron…
Landau theory of quantum spin glasses of rotors and Ising spins
N. Read, S. Sachdev, J. Ye
We consider quantum rotors or Ising spins in a transverse field on a -dimensional lattice, with random, frustrating, short-range, exchange interactions. The quantum dynamics are…
Triviality of the ground-state metastate in long-range Ising spin glasses in one dimension
N. Read
We consider the one-dimensional model of a spin glass with independent Gaussian-distributed random interactions, that have mean zero and variance , between the spins…
Rotating spin-1 bosons in the lowest Landau level
J. W. Reijnders, F. J. M van Lankvelt, K. Schoutens +1
We present results for the ground states of a system of spin-1 bosons in a rotating trap. We focus on the dilute, weakly interacting regime, and restrict the bosons to the quantum…
Absence of a metallic phase in random-bond Ising models in two dimensions: applications to disordered superconductors and paired quantum Hall states
N. Read, Andreas W. W. Ludwig
When the two-dimensional random-bond Ising model is represented as a noninteracting fermion problem, it has the same symmetries as an ensemble of random matrices known as class D.…
Theory of minimum spanning trees II: exact graphical methods and perturbation expansion at the percolation threshold
T. S. Jackson, N. Read
Continuing the program begun by the authors in a previous paper, we develop an exact low-density expansion for the random minimum spanning tree (MST) on a finite graph, and use it…
Associative-algebraic approach to logarithmic conformal field theories
N. Read, H. Saleur
We set up a strategy for studying large families of logarithmic conformal field theories by using the enlarged symmetries and non--semi-simple associative algebras appearing in the…
Bimodule structure in the periodic gl(1|1) spin chain
A. M. Gainutdinov, N. Read, H. Saleur
This paper is second in a series devoted to the study of periodic super-spin chains. In our first paper at 2011, we have studied the symmetry algebra of the periodic gl(1|1) spin c…
The periodic sl(2|1) alternating spin chain and its continuum limit as a bulk Logarithmic Conformal Field Theory at c=0
A. M. Gainutdinov, N. Read, H. Saleur +1
The periodic sl(2|1) alternating spin chain encodes (some of) the properties of hulls of percolation clusters, and is described in the continuum limit by a logarithmic conformal fi…
Non-Abelian adiabatic statistics and Hall viscosity in quantum Hall states and p_x+ip_y paired superfluids
N. Read
Many trial wavefunctions for fractional quantum Hall states in a single Landau level are given by functions called conformal blocks, taken from some conformal field theory. Also, w…
Comment on "Elementary formula for the Hall conductivity of interacting systems"
Steven H. Simon, Fenner Harper, N. Read
In a recent paper by Neupert, Santos, Chamon, and Mudry [Phys. Rev. B 86, 165133 (2012)] it is claimed that there is an elementary formula for the Hall conductivity of fractional C…
Thermal metal in network models of a disordered two-dimensional superconductor
J. T. Chalker, N. Read, V. Kagalovsky +3
We study the universality class for localization which arises from models of non-interacting quasiparticles in disordered superconductors that have neither time-reversal nor spin-r…
Paired states of fermions in two dimensions with breaking of parity and time-reversal symmetries, and the fractional quantum Hall effect
N. Read, Dmitry Green
We analyze pairing of fermions in two dimensions for fully-gapped cases with broken parity (P) and time-reversal (T), especially cases in which the gap function is an orbital angul…
Condensation of fractional excitons, non-Abelian states in double-layer quantum Hall systems and Z_4 parafermions
Edward Rezayi, Xiao-Gang Wen, N. Read
In this paper, we study a method to obtain non-Abelian FQH state through double-layer FQH states and fractional exciton condensation. In particular, we find that starting with the…
The traveling salesman problem, conformal invariance, and dense polymers
J. L. Jacobsen, N. Read, H. Saleur
We propose that the statistics of the optimal tour in the planar random Euclidean traveling salesman problem is conformally invariant on large scales. This is exhibited in power-la…
Localization in disordered superconducting wires with broken spin-rotation symmetry
Ilya A. Gruzberg, N. Read, Smitha Vishveshwara
Localization and delocalization of non-interacting quasiparticle states in a superconducting wire are reconsidered, for the cases in which spin-rotation symmetry is absent, and tim…
Dense loops, supersymmetry, and Goldstone phases in two dimensions
J. L. Jacobsen, N. Read, H. Saleur
Loop models in two dimensions can be related to O(N) models. The low-temperature dense-loops phase of such a model, or of its reformulation using a supergroup as symmetry, can have…
Nonabelian braid statistics versus projective permutation statistics
N. Read
Recent papers by Finkelstein, Galiautdinov, and coworkers {[J. Math. Phys. 42, 1489, 3299 (2001)]} discuss a suggestion by Wilczek that nonabelian projective representations of the…
Theory of minimum spanning trees I: Mean-field theory and strongly disordered spin-glass model
T. S. Jackson, N. Read
The minimum spanning tree (MST) is a combinatorial optimization problem: given a connected graph with a real weight ("cost") on each edge, find the spanning tree that minimizes the…
Behaviour of the energy gap near a commensurate-incommensurate transition in double layer quantum Hall systems at nu=1
N. Read
The charged excitations in the system of the title are vortex-antivortex pairs in the spin-texture described in the theory by Yang et al which, in the commensurate phase, are bound…
Logarithmic Conformal Field Theory: a Lattice Approach
A. M. Gainutdinov, J. L. Jacobsen, N. Read +2
Logarithmic Conformal Field Theories (LCFT) play a key role, for instance, in the description of critical geometrical problems (percolation, self avoiding walks, etc.), or of criti…
Minimum spanning trees and random resistor networks in d dimensions
N. Read
We consider minimum-cost spanning trees, both in lattice and Euclidean models, in d dimensions. For the cost of the optimum tree in a box of size L, we show that there is a correct…
Rezayi and Read Reply
E. Rezayi, N. Read
Reply to comment by Jain, Cond-mat 9409012 published in the Physical Review Letters, Number 73, 1052 (1994).
Vortex lattices in the lowest Landau level for confined Bose-Einstein condensates
N. R. Cooper, S. Komineas, N. Read
We present the results of numerical calculations of the groundstates of weakly-interacting Bose-Einstein condensates containing large numbers of vortices. Our calculations show tha…
Universality classes of dense polymers and conformal sigma models
C. Candu, J. L. Jacobsen, N. Read +1
In the usual statistical model of a dense polymer (a single space-filling loop on a lattice) in two dimensions the loop does not cross itself. We modify this by including intersect…
Theory of the half-filled Landau level
N. Read
A recent theory of a compressible Fermi-liquid like state at Landau level filling factors or , even, is reviewed, with emphasis on the basic physical concepts.
Hall viscosity, orbital spin, and geometry: paired superfluids and quantum Hall systems
N. Read, E. H. Rezayi
The Hall viscosity, a non-dissipative transport coefficient analogous to Hall conductivity, is considered for quantum fluids in gapped or topological phases. The relation to mean o…
Bilayer Quantum Hall States at and Coulomb Drag
Yong Baek Kim, Chetan Nayak, Eugene Demler +2
We consider a number of strongly-correlated quantum Hall states which are likely to be realized in bilayer quantum Hall systems at total Landau level filling fraction . O…
Compactly-supported Wannier functions and algebraic -theory
N. Read
In a tight-binding lattice model with orbitals (single-particle states) per site, Wannier functions are -component vector functions of position that fall off rapidly away fr…
Beyond paired quantum Hall states: parafermions and incompressible states in the first excited Landau level
N. Read, E. Rezayi
The Pfaffian quantum Hall states, which can be viewed as involving pairing either of spin-polarized electrons or of composite fermions, are generalized by finding the exact ground…
Conformal invariance of chiral edge theories
N. Read
The low-energy effective quantum field theory of the edge excitations of a fully-gapped bulk topological phase corresponding to a local interaction Hamiltonian must be local and un…
Fractional Chern Insulators in Bands with Zero Berry Curvature
Steven H. Simon, Fenner Harper, N. Read
Even if a noninteracting system has zero Berry curvature everywhere in the Brillouin zone, it is possible to introduce interactions that stabilise a fractional Chern insulator. The…
One-step replica-symmetry-breaking phase below the de Almeida-Thouless line in low-dimensional spin glasses
J. Höller, N. Read
The de Almeida-Thouless (AT) line is the phase boundary in the temperature--magnetic field plane of an Ising spin glass at which a continuous (i.e. second-order) transition from a…
Non-Hermitian adiabatic transport in spaces of exceptional points
J. Höller, N. Read, J. G. E. Harris
We consider the space of non-Hermitian Hamiltonians (, , . . .) that are equivalent to a single Jordan block. We focus on adiabatic transport aroun…
Edge state inner products and real-space entanglement spectrum of trial quantum Hall states
J. Dubail, N. Read, E. H. Rezayi
We consider the trial wavefunctions for the Fractional Quantum Hall Effect (FQHE) that are given by conformal blocks, and construct their associated edge excited states in full gen…
Mesoscopic conductance and its fluctuations at non-zero Hall angle
Shanhui Xiong, N. Read, A. Douglas Stone
We consider the bilocal conductivity tensor, the two-probe conductance and its fluctuations for a disordered phase-coherent two-dimensional system of non-interacting electrons in t…
Multicritical point on the de Almeida-Thouless line in spin glasses in dimensions
M. A. Moore, N. Read
The de Almeida-Thouless (AT) line in Ising spin glasses is the phase boundary in the temperature and magnetic field plane below which replica symmetry is broken. Using pert…
Short-range Ising spin glasses: the metastate interpretation of replica symmetry breaking
N. Read
Parisi's formal replica-symmetry--breaking (RSB) scheme for mean-field spin glasses has long been interpreted in terms of many pure states organized ultrametrically. However, the e…
Real-space entanglement spectrum of quantum Hall systems
J. Dubail, N. Read, E. H. Rezayi
We study the real-space entanglement spectrum for fractional quantum Hall systems, which maintains locality along the spatial cut, and provide evidence that it possesses a scaling…
Conductance and its universal fluctuations in the directed network model at the crossover to the quasi-one-dimensional regime
Ilya A. Gruzberg, N. Read, Subir Sachdev
The directed network model describing chiral edge states on the surface of a cylindrical 3D quantum Hall system is known to map to a one-dimensional quantum ferromagnetic spin chai…
Quasiholes and fermionic zero modes of paired fractional quantum Hall states: the mechanism for nonabelian statistics
N. Read, E. Rezayi
The quasihole states of several paired states, the Pfaffian, Haldane-Rezayi, and 331 states, which under certain conditions may describe electrons at filling factor or 5/2…
Scaling and Crossover Functions for the Conductance in the Directed Network Model of Edge States
Ilya A. Gruzberg, N. Read, Subir Sachdev
We consider the directed network (DN) of edge states on the surface of a cylinder of length L and circumference C. By mapping it to a ferromagnetic superspin chain, and using a sca…
Edge excitations of paired fractional quantum Hall states
M. Milovanovic, N. Read
The Hilbert spaces of the edge excitations of several ``paired'' fractional quantum Hall states, namely the Pfaffian, Haldane-Rezayi and 331 states, are constructed and the states…