Quantum Simulation and Quantum Synchronization
Tobias Kehrer, Tobias Nadolny, and Christoph Bruder
Quantum Theory Bruder Group, Department of Physics, University of Basel
Simulating (open) quantum systems on currently available NISQ hardware demands further control tools in addition to standard methods of quantum computation. Building customized pulse sequences grants full access to a quantum device in comparison to relying only on xed prede ned gates.
We are working on several approaches to improve quantum simulations. In [1], synchronization of a spin-1 oscillator with an external drive was implemented on a superconducting IBMQ device. Here, we present preliminary data on a proof-of-principle measurement suggesting that we can e ectively reduce the T1 relaxation time of an IBMQ device, lifting one of the main limitations of [1]. We implement a circuit which we call loud echo. It is based on an echo sequence [2] used to prepare a qubit in a mixed state. Applying appropriate constant drives during echo delay periods, we can reduce T1 approximately by a factor of two.
In addition to extending implementations of quantum synchronization to e.g. multiple oscillators, we are working on improving (multi-qubit) gates and readout sequences.
References
[1] M. Koppenhofer, C. Bruder, and A. Roulet. Quantum synchronization on the IBM Q system. Physical Review Research, 2(2):023026, Apr. 2020.
[2] B. Rost, B. Jones, M. Vyushkova, A. Ali, C. Cullip, A. Vyushkov, and J. Nabrzyski. Simulation of Thermal Relaxation in Spin Chemistry Systems on a Quantum Computer Using Inherent Qubit Decoherence. arXiv e-prints, page arXiv:2001.00794, Jan. 2020.