Types of Quantum Errors
Understand the errors that challenge quantum computation
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Hardware Platform Comparison
Introduction to Quantum Errors
Quantum computers are extremely fragile. Unlike classical bits that are either 0 or 1, quantum states exist in superposition and can be corrupted in infinitely many ways. Understanding error types is the first step toward quantum error correction.
6
Major Error Types
0.1%
Typical Error Rate
∞
Possible Errors
99%
Target Fidelity
Why Errors Matter
⚠️
Quantum Fragility
Quantum states are exponentially sensitive to noise
📉
Error Accumulation
Errors compound over circuit depth
🎯
Algorithm Failure
High error rates destroy quantum advantage
🔧
Correction Overhead
More errors require more correction resources
Error Categories
1
Coherent Errors
Deterministic errors from imperfect control (gates, timing)
Example: Over-rotation by 1° in X-gate
2
Incoherent Errors
Random errors from environmental noise (decoherence)
Example: Random phase flip from magnetic field
3
Measurement Errors
Errors in reading out the quantum state
Example: Reading |1⟩ when state is |0⟩
4
Leakage Errors
Qubit escapes computational subspace
Example: Transition to |2⟩ state in transmon
Error Rate Comparison
Total Error Rate:0.1% - 1%
Gate Fidelity:99% - 99.9%