雅思阅读 · Quantum Computing: The Next Revolution

科技主题。题型：选择题 + T/F/NG。难度：较难（P3）。

正文 Passage

For decades, computers have followed the same basic principle: information is stored and processed as a series of ones and zeros, called bits. Every photo, every email, every piece of software is ultimately a long string of these binary digits. Quantum computing promises to upend this entirely.

Instead of bits, quantum computers use qubits. Unlike a classical bit, which is either 0 or 1, a qubit can exist in a state called "superposition" — effectively both 0 and 1 at the same time. This means that a quantum computer with n qubits can perform 2ⁿ calculations simultaneously, a degree of parallelism that classical machines cannot match.

The implications are enormous. Certain problems — factoring large numbers, simulating molecular structures, optimising complex systems — that would take a classical supercomputer thousands of years could be solved by a quantum machine in hours. This is why governments and technology companies have poured billions into quantum research. A sufficiently powerful quantum computer could break the encryption that protects most of the world's internet traffic.

But the challenges are immense. Qubits are extraordinarily fragile. They must be kept at temperatures close to absolute zero — colder than deep space — and isolated from any vibration, electromagnetic field or even stray light. A single particle of heat can collapse a qubit's state, an event known as "decoherence". For this reason, quantum computers today are small, error-prone and far from practical usefulness.

Researchers are pursuing several approaches to building stable qubits, from superconducting circuits to trapped ions to photons travelling through silicon. No clear winner has emerged. Even the most optimistic estimates suggest that a large-scale, error-corrected quantum computer is at least a decade away, perhaps longer.

Sceptics argue that quantum computing may never live up to its hype, much as artificial intelligence in the 1970s failed to deliver on its early promises. Supporters counter that the physics is sound — it is an engineering problem, not a theoretical one — and that once the kinks are worked out, the transformation will be as profound as the move from vacuum tubes to microchips.

Either way, quantum computing is no longer science fiction. It is a slowly maturing technology that will, sooner or later, force us to rethink what a computer is — and what it can do.

题目 Questions

Questions 1-3: Choose the correct letter, A, B, C or D.

1. What is a qubit?

• A. a classical bit that is faster
• B. a quantum bit that can be both 0 and 1 simultaneously
• C. a type of microchip
• D. a unit of data storage

2. Why are qubits fragile?

• A. they are too large
• B. they require extremely cold temperatures and isolation
• C. they use too much power
• D. they cannot be programmed

3. According to the passage, large-scale quantum computers...

• A. are already widely used
• B. will never be built
• C. are at least ten years away
• D. replaced classical computers in 2025

Questions 4-7: T/F/NG

4. A quantum computer with n qubits can perform 2ⁿ calculations at the same time.

5. A quantum computer could potentially break internet encryption.

6. Researchers have already found the best way to build qubits.

7. All experts agree that quantum computing will be a failure.

Questions 8-10: Complete the notes. NO MORE THAN TWO WORDS.

• Qubits must be kept near (8) ____________.
• The collapse of a qubit's state is called (9) ____________.
• Sceptics compare quantum computing to early (10) ____________.

答案 Answers

核心词汇

quantum / qubit / superposition / parallelism / factoring / encryption / fragile / absolute zero / decoherence / superconducting / trapped ion / photon / silicon / sceptic / hype