Dresden 2017 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 38: Transport: Quantum Coherence and Quantum Information Systems - Experiment (jointly with MA, HL)

TT 38.8: Talk

Wednesday, March 22, 2017, 11:30–11:45, HSZ 03

Tailoring coupling in artificial superconducting quasi-spins — •Alexander Stehli, Jochen Braumüller, Andre Schneider, Hannes Rotzinger, Martin Weides, and Alexey V. Ustinov — Physikalisches Institut, Karlsruhe Institute of Technology

Due to their intrinsic coherence and easy accessibility, superconducting circuits are a promising platform for building a universal quantum computer. Such devices could solve virtually any quantum problem, however many qubits are required in order to achieve quantum supremacy. A more direct, alternative approach is provided by analog quantum simulation. By synthesizing the Hamiltonian of a quantum system with a simulator, the eigenstates and time evolution are investigated without accessing the original system.

In this work, we explore the properties of two coupled concentric transmon qubits. We show strong XX-interaction with a coupling strength of 12 MHz between the qubits. This value is extracted from spectroscopy measurements and confirmed by vacuum Rabi oscillations, in good agreement with electrodynamic calculations.

These results pave way towards future experiments on the quantum dynamics of larger systems with multiple artificial quasi-spins. The concentric transmon is expected also to feature ZZ-coupling, when biased at frequencies away from the flux sweet spot. Depending on the accessible parameter range, the simulation of the Fermi-Hubbard model is offered by a theoretical model. In this contribution, we will show our experimental and numerical data and provide an outlook on performing quantum simulation with concentric transmon qubits.