Publication

We investigate the real-time dynamics of the $(1+1)$-dimensional $U(1)$ gauge theory known as the Schwinger model via variational quantum algorithms.

We lower bound the circuit depth or time required for quantum routing in terms of spectral properties of graphs representing the architecture interaction constraints, and give a generalized upper bound for all simple connected $n$-vertex graphs.

We propose a time-independent Hamiltonian protocol for the reversal of qubit ordering in a chain of $N$ spins.

We present methods for implementing arbitrary permutations of qubits under interaction constraints.

In this work, we explore connections between various “analog” quantum optimization algorithms such as QAOA and annealing, and the limits in which they become approximations of the optimal control strategy.

We study the dynamics and practical performance of a quantum-inspired “local tensor” algorithm for approximate optimization of MaxCut problem instances.

We carry out simulations of optimal control protocols for energy minimization on various transverse field Ising models, demonstrating that optimal protocols typically exhibit a bang-anneal-bang pattern.

We implement a variational quantum algorithm (QAOA) to approximate the ground-state energy of a long-range Ising model, both quantum and classical, and investigating the algorithm performance on a trapped-ion quantum simulator with up to 40 qubits.

In this paper, we show that a quantity known as the isoperimetric number establishes a lower bound on the time required to create highly entangled states.

We present numerical and analytical results on the speed at which large entangled states can be created on nearest-neighbor grids and hierarchy graphs. We also present a scheme for performing circuit placement on hierarchical quantum architectures.