Accurately computing electronic properties of a quantum ring
Abstract
A promising approach to study condensed-matter systems is to simulate them on an engineered quantum platform. However, achieving the accuracy needed to outperform classical methods has been an outstanding challenge. Here, using eighteen superconducting qubits, we provide an experimental blueprint for an accurate condensed-matter simulator and demonstrate how to probe fundamental electronic properties. We benchmark the underlying method by reconstructing the single-particle band-structure of a one-dimensional wire. We demonstrate nearly complete mitigation of decoherence and readout errors and arrive at an accuracy in measuring energy eigenvalues of this wire with an error of ~0.01 rad, whereas typical energy scales are of order 1 rad. Insight into this unprecedented algorithm fidelity is gained by highlighting robust properties of a Fourier transform, including the ability to resolve eigenenergies with a statistical uncertainty of 1e-4 rad. Furthermore, we synthesize magnetic flux and disordered local potentials, two key tenets of a condensed-matter system. When sweeping the magnetic flux, we observe avoided level crossings in the spectrum, a detailed fingerprint of the spatial distribution of local disorder. Combining these methods, we reconstruct electronic properties of the eigenstates where we observe persistent currents and a strong suppression of conductance with added disorder. Our work describes an accurate method for quantum simulation and paves the way to study novel quantum materials with superconducting qubits.
Cite
@article{arxiv.2012.00921,
title = {Accurately computing electronic properties of a quantum ring},
author = {C. Neill and T. McCourt and X. Mi and Z. Jiang and M. Y. Niu and W. Mruczkiewicz and I. Aleiner and F. Arute and K. Arya and J. Atalaya and R. Babbush and J. C. Bardin and R. Barends and A. Bengtsson and A. Bourassa and M. Broughton and B. B. Buckley and D. A. Buell and B. Burkett and N. Bushnell and J. Campero and Z. Chen and B. Chiaro and R. Collins and W. Courtney and S. Demura and A. R. Derk and A. Dunsworth and D. Eppens and C. Erickson and E. Farhi and A. G. Fowler and B. Foxen and C. Gidney and M. Giustina and J. A. Gross and M. P. Harrigan and S. D. Harrington and J. Hilton and A. Ho and S. Hong and T. Huang and W. J. Huggins and S. V. Isakov and M. Jacob-Mitos and E. Jeffrey and C. Jones and D. Kafri and K. Kechedzhi and J. Kelly and S. Kim and P. V. Klimov and A. N. Korotkov and F. Kostritsa and D. Landhuis and P. Laptev and E. Lucero and O. Martin and J. R. McClean and M. McEwen and A. Megrant and K. C. Miao and M. Mohseni and J. Mutus and O. Naaman and M. Neeley and M. Newman and T. E. O'Brien and A. Opremcak and E. Ostby and B. Pato and A. Petukhov and C. Quintana and N. Redd and N. C. Rubin and D. Sank and K. J. Satzinger and V. Shvarts and D. Strain and M. Szalay and M. D. Trevithick and B. Villalonga and T. C. White and Z. Yao and P. Yeh and A. Zalcman and H. Neven and S. Boixo and L. B. Ioffe and P. Roushan and Y. Chen and V. Smelyanskiy},
journal= {arXiv preprint arXiv:2012.00921},
year = {2021}
}