11 papers
Imaginarity as a necessary resource for trainability in QAOA
Syed Muhammad Ali Hassan, Kostas Blekos, Stefan Kühn +2
The quantum approximate optimization algorithm (QAOA) tackles combinatorial problems by tuning a quantum circuit in a classical loop, often guided by gradients. We show that the gr…
Warm Start of Variational Quantum Algorithms for Quadratic Unconstrained Binary Optimization Problems
Yahui Chai, Karl Jansen, Stefan Kühn +2
Variational Quantum Eigensolver (VQE) is widely used in near-term hardware. However, their performances remain limited by the poor trainability and are dependent on random paramete…
Matching Lagrangian and Hamiltonian Simulations in (2+1)-dimensional U(1) Gauge Theory
C. F. GroÃ, S. Romiti, L. Funcke +4
At finite lattice spacing, Lagrangian and Hamiltonian predictions differ due to discretization effects. In the Hamiltonian limit, i.e. at vanishing temporal lattice spacing ,…
Barren-plateau free variational quantum simulation of Z2 lattice gauge theories
Fariha Azad, Matteo Inajetovic, Stefan Kühn +1
In this work, we design a variational quantum eigensolver (VQE) suitable for investigating ground states and static string breaking in a lattice gauge theory (LGT).…
Resource-Efficient Simulations of Particle Scattering on a Digital Quantum Computer
Yahui Chai, Joe Gibbs, Vincent R. Pascuzzi +4
We develop and demonstrate methods for simulating the scattering of particle wave packets in the interacting Thirring model on digital quantum computers, with hardware implementati…
Hamiltonian Lattice Formulation of Compact Maxwell-Chern-Simons Theory
Changnan Peng, Maria Cristina Diamantini, Lena Funcke +6
In this paper, a Hamiltonian lattice formulation for 2+1D compact Maxwell-Chern-Simons theory is derived. We analytically solve this theory and demonstrate that the mass gap in the…