Quantum Computer With N-State Bosonic Cat Encoding for Error Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing quantum computing systems face challenges in balancing the need for isolating quantum information from the environment to prevent decoherence while also allowing controlled interactions for processing, leading to costly redundancy solutions and inadequate error correction for bit-flip and phase-flip errors, particularly in bosonic cat-state encodings.
Innovation Solution
A method is proposed to encode quantum information using a bosonic cat state with N coherent states, where N>2, defining a computational space with logical states that are rotationally asymmetric, allowing phase shifts to lead to distinct modified states outside the logical subspace or back to the initial state, thereby detecting and correcting errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If quantum information is isolated from the environment to prevent decoherence, then quantum information stability is improved, but the ability to process and control quantum information deteriorates
Solution Approach 1:
The quantum system is segmented into distinct logical qubits encoded within a single bosonic mode, where each logical state corresponds to specific phase-space regions. This segmentation allows the system to maintain isolation for stability while enabling controlled processing through selective manipulation of logical states within the segmented phase space.
Solution Approach 2:
The patent introduces an intermediary encoding scheme where quantum information is represented through bosonic cat states with N>2 coherent states. This intermediary representation acts as a buffer between the isolated quantum system and control operations, allowing processing through phase-space transformations without requiring direct environmental interaction that would cause decoherence.
2Reliability
If redundancy is used to correct quantum errors, then error correction capability is improved, but system resource requirements deteriorate
Solution Approach 1:
Multiple logical qubits are merged into a single bosonic mode through bosonic cat-state encoding. Instead of using separate physical qubits for each logical qubit, the patent combines multiple logical states within one bosonic system, significantly reducing the physical resources required while maintaining error correction capabilities through the inherent redundancy of the cat-state structure.
Solution Approach 2:
The patent implements a nested structure where logical qubits are encoded within the phase space of a single bosonic mode. The logical states are nested within the coherent states, which are themselves nested within the bosonic Fock space, creating a hierarchical encoding that maximizes information density while minimizing physical resource requirements.
3Reliability
If cat-state encoding with N>2 coherent states is used, then error detection capability is improved, but system complexity deteriorates
Solution Approach 1:
The patent employs asymmetric encoding where N>2 coherent states are distributed non-uniformly in phase space with rotationally asymmetric logical state definitions. This asymmetry breaks the symmetry of standard cat-state encoding, enabling enhanced error detection capability by creating distinct signatures for different error types, while the systematic approach to asymmetric encoding keeps the implementation complexity manageable.
Data Source
AI summary
The system can include a quantum subsystem drivable to host a bosonic cat state having N coherent states wherein N is greater than two, the N coherent states defining a computational space; a controller operably connected to control driving hardware in accordance with control instructions, wherein at least one interaction type between the bosonic cat state and an environment which do not stem from the control instructions lead to phase shifting of the N coherent states, wherein the control instructions include a function to generate an initial state of the bosonic cat state defined as a given superposition of two distinct logical states representing logical information, the two distinct logical states spanning a logical subspace within the computational space, wherein any phase shifting from the initial state either leads to a modified state which lies outside the logical subspace while preserving said logical information, or back to the initial state.