711 research outputs found
Foliated Field Theory and String-Membrane-Net Condensation Picture of Fracton Order
Foliated fracton order is a qualitatively new kind of phase of matter. It is
similar to topological order, but with the fundamental difference that a
layered structure, referred to as a foliation, plays an essential role and
determines the mobility restrictions of the topological excitations. In this
work, we introduce a new kind of field theory to describe these phases: a
foliated field theory. We also introduce a new lattice model and
string-membrane-net condensation picture of these phases, which is analogous to
the string-net condensation picture of topological order.Comment: 22+15 pages, 8 figures; v3 added a summary of our model near the end
of the introductio
Anomalies and entanglement renormalization
We study 't Hooft anomalies of discrete groups in the framework of
(1+1)-dimensional multiscale entanglement renormalization ansatz states on the
lattice. Using matrix product operators, general topological restrictions on
conformal data are derived. An ansatz class allowing for optimization of MERA
with an anomalous symmetry is introduced. We utilize this class to numerically
study a family of Hamiltonians with a symmetric critical line. Conformal data
is obtained for all irreducible projective representations of each anomalous
symmetry twist, corresponding to definite topological sectors. It is
numerically demonstrated that this line is a protected gapless phase. Finally,
we implement a duality transformation between a pair of critical lines using
our subclass of MERA.Comment: 12+18 pages, 6+5 figures, 0+2 tables, v2 published versio
Symmetry-protected adiabatic quantum transistors
The standard circuit model of quantum computation differs in principle from a modern day computer chip in that computation is brought to stationary qubits in the former whereas information is routed spatially across a chip by transistors in the latter. Recently a model was proposed that addresses this key difference in implementation, it was dubbed the adiabatic quantum transistor model to emphasise its similarity to a classical transistor. Here we generalise this model to the setting of spin chains in inherently quantum phases of matter with a property called symmetry-protected order. Our generalisation is significant as it shows the computational properties of the model persist robustly throughout each symmetry-protected quantum phase of matter
- …