INQA Conference 2025: Madhumita Sarkar - University College London

Title: Harnessing Continuous-Time Quantum Dynamics for Engineering High-Fidelity State Transfer and Preparing Many-body Quantum Bound States

Abstract: Analog quantum computation and simulation, rooted in continuoustime quantum evolution, provide a powerful framework for exploring strongly correlated systems and advancing scalable quantum technologies. We explore two complementary theoretical studies at the interface of solid-state qubits and correlated electron systems.
First, we investigate semiconductor spin qubits, which combine long coherence times with compatibility with industrial fabrication. However, in
hole-based qubits, strong spin–orbit coupling induces anisotropic exchange interactions, breaking the conventional Heisenberg description and hindering coherent control and entanglement transfer. We present a systematic approach to address this challenge by deriving an exact effective Hamiltonian that captures the role of anisotropy in quantum state transfer and entanglement dynamics. Extending this framework to multi-qubit chains, we identify protocols for high-fidelity long-distance quantum information transfer with minimal external control, showing that anisotropy can be harnessed as a resource for analog quantum information channels.
Second, we investigate bound states in doped Mott insulators using a generalized t–J model derived via the Schrieffer–Wolff transformation. We
show how continuous-time quantum dynamics, including external periodic
driving, can be harnessed to tune both the binding energies and lifetimes of
excitonic states. These findings suggest experimentally accessible protocols for realizing and controlling Hubbard excitons in cold-atom platforms, offering a pathway to explore engineered many-body states in analog quantum simulators.
Together, these studies show how continuous-time quantum dynamics can be used for both reliable quantum information transfer and controlled many-body bound state formation.