104 research outputs found
Oscillation and decay of particle current due to a quench and dephasing in an interacting fermionic system
We study the response of a particle current to dissipative dephasing in an
interacting, few-body fermionic lattice system. The particles are prepared in
the ground state in presence of an artificial magnetic gauge field, which is
subsequently quenched to zero. The initial current decays non-trivially in the
dissipative environment and we explore the emerging dynamics and its dependence
on various system parameters.Comment: 6 pages, 5 figures, submitted to European Physical Journal: Special
Topic (EPJ-ST
Measurement of the entanglement spectrum of a symmetry-protected topological state using the IBM quantum computer
Entanglement properties are routinely used to characterize phases of quantum
matter in theoretical computations. For example the spectrum of the reduced
density matrix, or so-called "entanglement spectrum", has become a widely used
diagnostic for universal topological properties of quantum phases. However,
while being convenient to calculate theoretically, it is notoriously hard to
measure in experiments. Here we use the IBM quantum computer to make the first
ever measurement of the entanglement spectrum of a symmetry-protected
topological state. We are able to distinguish its entanglement spectrum from
those we measure for trivial and long-range ordered states.Comment: 8 pages, 4 figure
Neural Network Evolution Strategy for Solving Quantum Sign Structures
Feed-forward neural networks are a novel class of variational wave functions
for correlated many-body quantum systems. Here, we propose a specific neural
network ansatz suitable for systems with real-valued wave functions. Its
characteristic is to encode the all-important rugged sign structure of a
quantum wave function in a convolutional neural network with discrete output.
Its training is achieved through an evolutionary algorithm. We test our
variational ansatz and training strategy on two spin-1/2 Heisenberg models, one
on the two-dimensional square lattice and one on the three-dimensional
pyrochlore lattice. In the former, our ansatz converges with high accuracy to
the analytically known sign structures of ordered phases. In the latter, where
such sign structures are a priory unknown, we obtain better variational
energies than with other neural network states. Our results demonstrate the
utility of discrete neural networks to solve quantum many-body problems
Poster: Improving communication and communicability with smarter use of text-based messages on mobile and wearable devices
Ministry of Education, Singapore under its Academic Research Funding Tier 2; Singapore National Research Foundation under IDM Futures Funding Initiativ
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