量子隐形传态如何利用纠缠实现未知量子态的转移？
How does quantum teleportation transfer an unknown quantum state using entanglement?
隐形传态借助一对共享纠缠粒子和一次贝尔基测量，把未知态的「信息」从发送方转移到接收方，原粒子态随之坍缩。它传输的是量子态而非物质，且必须配合一条经典信道才能复原态。
Teleportation uses a shared entangled pair plus a Bell-basis measurement to move the information of an unknown state from sender to receiver, collapsing the original. It transfers the quantum state, not matter, and requires a classical channel to reconstruct it.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
《现代物理学评论》(Reviews of Modern Physics) — 量子信息综述
Reviews of Modern Physics — quantum information review
#量子隐形传态 #纠缠 #贝尔基测量
量子密钥分发基于什么原理让窃听可被检测？
On what principle does quantum key distribution make eavesdropping detectable?
以BB84协议为代表的量子密钥分发利用单光子的不可克隆定理和测量扰动：窃听者的测量会改变量子态并引入误码，通信双方据此发现并丢弃被窃听的数据。其安全性建立在量子力学定律而非计算难度之上。
QKD such as BB84 relies on the no-cloning theorem and measurement disturbance: an eavesdropper's measurement alters the quantum state and introduces errors the parties can detect and discard. Its security rests on the laws of quantum mechanics, not computational hardness.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
曾谨言,《量子力学 卷I》,科学出版社,2013
Zeng Jinyan, Quantum Mechanics Vol.I, Science Press, 2013
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787030387226（按标识回读: 量子力学 卷1）
#量子密钥分发 #不可克隆定理 #BB84
为什么量子计算需要量子纠错码？基本原理是什么？
Why do quantum computers need quantum error correction, and what is the basic principle?
量子比特易受退相干和门错误影响，量子纠错把单个逻辑比特编码到多个物理比特的纠缠态中，用冗余检测并纠正错误而不直接测量脆弱的量子态。阈值定理表明只要物理错误率低于阈值，逻辑错误率可指数压低。
Qubits are vulnerable to decoherence and gate errors; quantum error correction encodes one logical qubit into an entangled state of many physical qubits, using redundancy to detect and correct errors without measuring the fragile state. The threshold theorem says logical error falls exponentially once physical error is below threshold.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Nature Physics — 量子纠错专题
Nature Physics — quantum error correction feature
#量子纠错 #退相干 #阈值定理
在贝尔态测量中,为什么对两个量子比特同时做局域测量无法区分全部四个贝尔态?
In Bell-state measurement, why can local measurements on two qubits alone never discriminate all four Bell states?
四个贝尔态构成两比特希尔伯特空间的一组最大纠缠正交基,而局域测量只能访问单个比特的约化密度矩阵。任意贝尔态的单比特约化密度矩阵都是相同的最大混合态 I/2,因此局域统计对它们完全简并。区分全部四个贝尔态必须引入两比特间的联合相互作用,例如通过 CNOT 门将贝尔基映射到计算基后再测量。
The four Bell states form a maximally entangled orthonormal basis of the two-qubit Hilbert space, while any local measurement accesses only the single-qubit reduced density matrix. Every Bell state yields the same maximally mixed reduced state I/2, so local statistics are fully degenerate across the quartet. Discriminating all four requires an entangling joint interaction — e.g. a CNOT that maps the Bell basis onto the computational basis before measurement.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
Nielsen & Chuang《Quantum Computation and Quantum Information》第4章量子隐形传态一节;Bennett et al., Phys. Rev. Lett. 70, 1895 (1993)
Nielsen & Chuang, Quantum Computation and Quantum Information, Ch.4 (teleportation); Bennett et al., Phys. Rev. Lett. 70, 1895 (1993)
独立核验依据 · Independent verification: 核验依据 1 ISBN 9780521635035 (2016)
#贝尔态测量 #纠缠判别
「薛定谔的猫」想说明量子叠加在什么尺度上难以观测？
What does Schrödinger's cat illustrate about where quantum superposition becomes hard to observe?
薛定谔用猫既死又活的叠加态讽刺宏观叠加的荒谬，揭示量子叠加在宏观尺度上会因与环境持续相互作用而快速退相干，变得无法观测。
Schrödinger's cat, both alive and dead, was a satire on macroscopic superposition, showing that at macroscopic scales quantum superposition decoheres rapidly through interaction with the environment and becomes unobservable.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
M. Schlosshauer,《退相干、测量问题与量子力学的诠释》, Reviews of Modern Physics 76, 1267 (2005)
M. Schlosshauer, Decoherence, the Measurement Problem, and Interpretations of Quantum Mechanics, Reviews of Modern Physics 76, 1267 (2005)
独立核验依据 · Independent verification: 核验依据 1 ARCHIVE 标识 arxiv-quant-ph0312059：Decoherence, the measur
#薛定谔猫 #退相干 #宏观叠加
量子比特与经典比特的根本区别是什么？
What is the fundamental difference between a qubit and a classical bit?
经典比特非0即1，量子比特可处于0和1的叠加态，并能与其他量子比特纠缠，从而在并行计算中表示指数级多的状态组合。测量才会让叠加态给出确定的0或1。
A classical bit is either 0 or 1, while a qubit can be in a superposition of 0 and 1 and entangle with others, representing exponentially many combinations in parallel. A measurement yields a definite 0 or 1.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录仅给书名，无版次与年份；同一书名常对应多个版次，不臆测具体版本。
《现代物理学评论》— 量子计算综述
Reviews of Modern Physics — quantum computing review
#量子比特 #叠加 #纠缠
量子力学中的「测量」为何会显著改变系统的结果？
Why does 'measurement' in quantum mechanics so strongly affect the outcome?
测量前系统处于多个本征态的叠加，测量会使系统以对应概率坍缩到某个本征态，得到确定读数。这种随机性与非决定性是量子力学区别于经典物理的核心特征。
Before measurement a system is in a superposition of eigenstates; measurement makes it collapse into one eigenstate with a definite probability, giving a definite reading. This randomness is a core feature that distinguishes quantum from classical physics.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 2 条独立证据
来源 · Source
《费曼物理学讲义》第三卷
The Feynman Lectures on Physics, Volume III
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-7382-0298-3 (2006 Pearson 版，原始版为1963-65 Addis
#量子测量 #波函数坍缩 #叠加态
什么是量子纠缠？我们如何实验验证它？
What is quantum entanglement, and how can it be experimentally verified?
量子纠缠指两个或多个粒子的量子态无法分解为各自独立态的乘积，测量其中一个会瞬间关联另一个的结果。实验上通过贝尔不等式的违背来验证，阿斯佩、蔡林格等人的光学实验提供了关键证据。
Quantum entanglement means the joint quantum state of two or more particles cannot be factored into independent states, so measuring one instantly correlates with the other. It is verified by violating a Bell inequality, as demonstrated in the optical experiments of Aspect, Zeilinger and others.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
曾谨言,《量子力学 卷I》,科学出版社,2013
Zeng Jinyan, Quantum Mechanics Vol.I, Science Press, 2013
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787030387226（按标识回读: 量子力学 卷1）
#量子纠缠 #贝尔不等式 #量子测量
贝尔定理为什么否定了局域隐变量理论？
Why does Bell's theorem rule out local hidden-variable theories?
贝尔定理证明，任何满足局域实在性的隐变量理论都无法重现量子力学对关联测量的全部预言。实验观测到的贝尔不等式违背只能用非局域性或放弃实在性来解释。
Bell's theorem proves that no local hidden-variable theory obeying local realism can reproduce all quantum correlation predictions. Observed Bell-inequality violations imply either non-locality or giving up realism.
难度 进阶 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
曾谨言,《量子力学 卷I》,科学出版社,2013
Zeng Jinyan, Quantum Mechanics Vol.I, Science Press, 2013
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787030387226（按标识回读: 量子力学 卷1）
#贝尔定理 #局域实在性 #非局域性
量子纠错码为什么必须用多个物理比特编码一个逻辑比特?表面码的优势在哪里?
Why must quantum error-correcting codes encode one logical qubit into many physical qubits, and what makes the surface code advantageous?
量子态不可克隆定理禁止直接复制未知量子态,而且量子错误既包括比特翻转也包括相位翻转,因此必须将逻辑信息非局域地分布到多个纠缠的物理比特上才能检测而不破坏信息。表面码把数据比特和测量比特布置在二维格点上,通过反复测量稳定子来提取错误症状,只需最近邻相互作用即可执行。它对单比特错误的容错阈值约为百分之一,是当前超导和离子阱平台上最实用的纠错方案之一。
The no-cloning theorem forbids copying unknown quantum states, and quantum errors include both bit flips and phase flips, so logical information must be distributed nonlocally across entangled physical qubits to enable detection without destroying the data. The surface code places data and measurement qubits on a two-dimensional lattice and repeatedly measures stabilizer operators to extract error syndromes, requiring only nearest-neighbor interactions. Its fault-tolerance threshold against single-qubit errors is roughly one percent, making it among the most practical schemes for superconducting and trapped-ion platforms today.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
A. G. Fowler et al., Phys. Rev. A 86, 032324 (2012): Surface codes: Towards practical large-scale quantum computation
A. G. Fowler et al., Phys. Rev. A 86, 032324 (2012): Surface codes: Towards practical large-scale quantum computation
独立核验依据 · Independent verification: 核验依据 1 DOI 10.1103/physreva.86.032324
#量子纠错 #表面码