首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
A key feature of quantum information science is the understanding that groups of two or more quantum objects can have sta
A key feature of quantum information science is the understanding that groups of two or more quantum objects can have sta
admin
2011-01-17
128
问题
A key feature of quantum information science is the understanding that
groups of two or more quantum objects can have states that are entangled, such
that the members of an entangled collection of objects do not have their own
Line individual quantum states, only the group as a whole. Although one can use the
(5) mathematics of quantum theory to reason about entanglement, there is a great
danger that the classical basis of our analogies will mislead us. Despite its
strangeness, for a long time entanglement was regarded as a curiosity and was
mostly ignored by physicists and this changed when Bell predicted and
confirmed that entangled quantum systems exhibit behavior that is impossible in
(10) a classical world-impossible even if one could change the laws of physics to try
to emulate the quantum predictions within a classical framework of any sort.
The idea that entanglement falls wholly outside the scope of classical physics
prompted researchers to ask whether entanglement might be useful as a
resource for solving information-processing problems in new ways.
(15) Entanglement measures improve how researchers can analyze tasks such as
quantum teleportation and algorithms on quantum-mechanical computers.
Classical computation and communications have a well-developed assortment of
error-correcting codes to protect information against the depredations of noise,
an example being the repetition code. This scheme represents the bit 0 as a
(20) string of three bits, 000, and the bit 1 as a string of three bits, 111. If the
noise is relatively weak, it may sometimes flip one of the bits in a triplet,
changing, for instance, 000 to 010, but it will flip two bits in a triplet far less
often. Whenever we encounter 010 (or 100 or 001), we can be almost certain
the correct value is 000, or 0.
(25) Initially it appeared to be impossible to develop codes for quantum error
correction because quantum mechanics forbids us from learning with certainty
the unknown state of a quantum object-the obstacle, again, of trying to
extract more than one bit from a quantum bit. One cannot examine each copy of
a quantum bit and see that one copy must be discarded without altering each and
(30) every copy in the process, and making the copies in the first place is nontrivial:
quantum mechanics forbids taking an unknown quantum bit and reliably making
a duplicate, a result known as the no-cloning theorem. Clever ideas developed
independently by Shor showed quantum error correction can be performed
without ever learning the states of the quantum bits or needing to clone them.
(35) As with the triplet code, each value is represented by a set of quantum bits and
it is as if one ran the triplet 010 through a circuit that could spot that the middle
bit was different and flip it "sight unseen".
The author suggests that, prior to Bell, the suggestion that entangled quantum systems exhibit behavior impossible in the world of classical physics would probably have been viewed with
选项
A、indignation
B、impatience
C、disbelief
D、indifference
E、defiance
答案
C
解析
转载请注明原文地址:https://www.kaotiyun.com/show/VxjO777K
本试题收录于:
GRE VERBAL题库GRE分类
0
GRE VERBAL
GRE
相关试题推荐
DuringatriptoobservewildanimalsinAfrica,Iencounteredtheleastbraveanimalonearth,thewildebeest(角马).Isatona
Traditionally,universitieshavecarriedouttwomainactivities:researchandteaching.Manyexpertswouldarguethatboththes
Thecardinalityofafinitesetisthenumberofelementsintheset.WhatisthecardinalityofsetA?(1)2isthecardinality
TheaverageageandracingexperienceofthedriversattheIndianapolis500automobileraceincreasedeachyearbetween1965an
EachofQuestions1to7presentstwoquantities.QuantityAandQuantityB.Comparethetwoquantities.Youmayuseadditional
MELLIFLUOUS:SOUND::
ACHROMATIC:HUE::
TheAmazonrainforestremained(i)______foryearsbecauseitssoilswereunsuitableforagricultureandbecauseendemicdisease
Becausehisthemesanduseofimageryarehighlyeccentric,painterSigmarPolkeissaidtohave______style.
Amisconceptionfrequentlyheldbynovicewritersisthatsentencestructuremirrorsthought:themoreconvolutedthestructure,
随机试题
逆流换热时,冷流体出口温度的最高极限值是()。
41.思维与存在的关系问题是历史观的基本问题。()
A.狭窄性腱鞘炎B.类风湿性关节炎C.髌骨软化症D.腰椎间盘突出症女,34岁,双手指关节晨起僵硬、疼痛,指关节肿胀、压痛,X线片示指骨骨质疏松,关节周围软组织肿胀阴影,诊断是
清燥救肺汤组成药物中无
经过审批部门批准应当采用邀请招标方式进行招标的是()。
苏州桃花坞木刻年画的主要形式不包括()。
国籍是一个人隶属于某个国家的法律上的身份。一旦具有某个国家的国籍,就被认为是该国的公民,享有该国宪法和法律规定的权利,承担该国宪法和法律规定的义务。下列关于国籍取得的表述,不正确的是()。
磁盘是种______存储器。
下列叙述中正确的是()。
Howdoesthewomanthinkaboutherboss?
最新回复
(
0
)