Suppressing errors is the central challenge for useful quantum computing[1], requiring quantum error correction[2][3][4][5][6]for large-scale processing.However, the overhead in the realization of error-corrected "logical" qubits, where information is encoded across many physical qubits for redundancy [2-4], poses significant challenges to large-scale logical quantum computing.Here we report the realization of a programmable quantum processor based on encoded logical qubits operating with up to 280 physical qubits.Utilizing logical-level control and a zoned architecture in reconfigurable neutral atom arrays [7], our system combines high two-qubit gate fidelities [8], arbitrary connectivity[7,9], as well as fully programmable single-qubit rotations and mid-circuit readout[10][11][12][13][14][15].Operating this logical processor with various types of encodings, we demonstrate improvement of a two-qubit logic gate by scaling surface code [6] distance from d = 3 to d = 7, preparation of color code qubits with break-even fidelities [5], fault-tolerant creation of logical GHZ states and feedforward entanglement teleportation, as well as operation of 40 color code qubits.Finally, using three-dimensional [[8,3,2]] code blocks[16,17], we realize computationally complex sampling circuits[18]with up to 48 logical qubits entangled with hypercube connectivity[19]with 228 logical two-qubit gates and 48 logical CCZ gates[20].We find that this logical encoding substantially improves algorithmic performance with error detection, outperforming physical qubit fidelities at both cross-entropy benchmarking and quantum simulations of fast scrambling[21,22].These results herald the advent of early error-corrected quantum computation and chart a path toward large-scale logical processors.
This paper presents a programmable quantum processor that uses encoded logical qubits constructed from reconfigurable neutral atom arrays. The system features up to 280 physical qubits, allowing for high fidelity two-qubit operations and scalability in logical operations. Experiments demonstrate fault-tolerant features through the operation of surface codes and color codes, achieving significant improvements in logical gate performance through correlated decoding techniques. The findings include various implementations of quantum algorithms, characterized by high fidelities and complex entangled states being generated through these logical operations. The research highlights the potential for practical implementations of early error-corrected quantum computation, paving the way for large-scale logical processors.
This paper employs the following methods:
- Quantum Error Correction
- Reconfigurable Atom Arrays
- Surface Codes
- Color Codes
- Correlated Decoding
The following datasets were used in this research:
- Realization of programmable quantum processor
- Demonstration of two-qubit logic gate improvements
- Preparation of logical GHZ states
- Operational performance of multi-qubit sampling circuits
- Observations of improved algorithmic performance with error detection
The authors identified the following limitations:
- Substantial overhead with physical qubit numbers
- Challenges in efficient control of logical qubits
- Non-fault-tolerant state preparation for certain code distances
- Number of GPUs: None specified
- GPU Type: None specified
- Compute Requirements: None specified