Simulation of mesoscopic quantum systems by liquid-state NMR

• Applicant: Professor Dr. Dieter Suter
• Subject Area: Experimental Condensed Matter Physics ; Theoretical Condensed Matter Physics
• Term: from 2006 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 18283631

Within this project, we will rely on liquid-state NMR, which appears to remain the most powerful technique for quantum information processing for the next few years. To develop the new quantum registers, we will identify molecules with suitable nuclear spin systems. For these molecules, we will evaluate the relevant NMR parameters (resonance frequencies, coupling constants, and relaxation times) and design suitable procedures for efficiently implementing algorithms. As the second major goal, we plan to use these medium-sized quantum processors for simulating specific properties of quantum mechanical systems, such as quantum phase transitions. For these simulations, the Hilbert space of the target system will be mapped into the states of the quantum register and the target Hamiltonian will be generated as an effective Hamiltonian by suitable multiple pulse sequences. Using these quantum simulators, we will explore the energy level structure of the target system as well as some dynamic aspects, like critical fluctuations near the phase transition. The present project aims to fill a gap between our recent studies on the scaling of decoherence in large quantum register models (up to 2000 qubits) and implementations of full quantum algorithms, where we were restricted to 2-3 qubit systems. Starting from moderate sized quantum registers, we will successively increase the number of qubits being controlled simultaneously and evaluate how the operation time and average decoherence rates change with increasing quantum register size. The increasing number of quantum gate operations and the increasing decoherence rate will require more efficient gate operations with higher fidelity. We therefore will study how control mechanisms can be optimized to retain the quantum information in the system for sufficiently long times.

• DFG Programme: Research Grants