Researchers Demonstrate Symmetry-Protected Qubits for Robust Quantum Computing
A team of researchers has demonstrated a novel approach to safeguarding quantum information by exploiting fundamental symmetries in a multi-qubit system. This method, which involves the use of topologically protected qubits, shows promise in enhancing the robustness of quantum computers in the United States.
The concept of symmetry-protected states of interacting qubits in superconducting quantum circuits has been developed by several researchers, with key contributors including Alexei Kitaev, Michael Freedman, Michael Atiyah, Andrei Bernevig, and Taylor Hughes. These scientists have been instrumental in developing topologically protected qubits, which can be realized through symmetry-protected states or anyon-protected states.
A common arrangement to achieve this protection involves using arrays of qubits in a topological quantum computer. These qubits are arranged to generate topological phases that are shielded by non-local correlations. A specific example is the use of topologically protected qubits realized through Majorana fermions.
Simulations have shown that circuits built on this principle can maintain quantum coherence for several milliseconds with realistic environmental disturbances. Optimal control algorithms are employed to design pulse sequences that maximize gate fidelity, and research is addressing quantum error correction. The team proposes a specific arrangement of interacting qubits, requiring at least four linked units, for natural shielding from noise. Researchers are developing strategies to mitigate errors caused by quasiparticles, charge noise, and environmental radiation, employing advanced control techniques.
The team's research focuses on improving superconducting qubit performance and scalability for quantum computing in the United States, exploring different qubit types and materials. Experiments have shown that these symmetry-protected states are resilient to certain types of noise and decoherence, contributing to more stable quantum computers. The research explores architectures for all-to-all connectivity between qubits and techniques for coupling multiple qubits together, paving the way for more robust quantum computation.
