Abstract
Although quantum computers can perform a wide range of practically important tasks beyond the abilities of classical computers1,2, realizing this potential remains a challenge. An example is to use an untrusted remote device to generate random bits that can be certified to contain a certain amount of entropy3. Certified randomness has many applications but is impossible to achieve solely by classical computation. Here we demonstrate the generation of certifiably random bits using the 56-qubit Quantinuum H2-1 trapped-ion quantum computer accessed over the Internet. Our protocol leverages the classical hardness of recent random circuit sampling demonstrations4,5: a client generates quantum ‘challenge’ circuits using a small randomness seed, sends them to an untrusted quantum server to execute and verifies the results of the server. We analyse the security of our protocol against a restricted class of realistic near-term adversaries. Using classical verification with measured combined sustained performance of 1.1 × 1018 floating-point operations per second across multiple supercomputers, we certify 71,313 bits of entropy under this restricted adversary and additional assumptions. Our results demonstrate a step towards the practical applicability of present-day quantum computers.
| Original language | English |
|---|---|
| Pages (from-to) | 343-348 |
| Number of pages | 6 |
| Journal | Nature |
| Volume | 640 |
| Issue number | 8058 |
| DOIs | |
| State | Published - Apr 10 2025 |
Funding
We thank J. Dimon, D. Pinto and L. Beer for their executive support of the Global Technology Applied Research Center of JPMorganChase and our work in Quantum Computing. We thank the technical staff at the Global Technology Applied Research Center of JPMorganChase for their invaluable contributions to this work. We are thankful to J. Gray for helpful discussions on tensor network contraction path optimization using CoTenGra. We acknowledge the entire Quantinuum team for their many contributions toward the successful operation of the H2 quantum computer with 56 qubits, and we acknowledge Honeywell for fabricating the trap used in this experiment. J.L., M.L., Y.A. and D.L. acknowledge support from the US Department of Energy, Office of Science, under contract DE-AC02-06CH11357 at Argonne National Laboratory and the US Department of Energy, Office of Science, National Quantum Information Science Research Centers. S.A. and S.-H.H. acknowledge the support from the US Department of Energy, Office of Science, National Quantum Information Science Research Centers and Quantum Systems Accelerator. T.S.H. was supported by the US Department of Energy, Office of Science, Advanced Scientific Computing Research program office under the quantum computing user program. This research used supporting resources at the Argonne and the Oak Ridge Leadership Computing Facilities. The Argonne Leadership Computing Facility at Argonne National Laboratory is supported by the Office of Science of the US DOE under contract no. DE-AC02-06CH11357. The Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory is supported by the Office of Science of the US DOE under contract no. DE-AC05-00OR22725. This research used resources of the National Energy Research Scientific Computing Center (NERSC), a Department of Energy Office of Science User Facility using NERSC award DDR-ERCAP0030284. The submitted manuscript includes contributions from UChicago Argonne, Operator of Argonne National Laboratory (‘Argonne’). Argonne, a US Department of Energy Office of Science laboratory, is operated under contract no. DE-AC02-06CH11357. The US government retains for itself, and others acting on its behalf, a paid-up nonexclusive, irrevocable worldwide licence in said Article to reproduce, prepare derivative works, distribute copies to the public and perform publicly and display publicly, by or on behalf of the government. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan http://energy.gov/downloads/doe-public-access-plan .