How It Works - UK (2020-02)

Despiteitsmuchsmallerscale,quantumteleportationbasically

functionslikeaStarTrektransporter.It createsa copyofa particleata

distantlocation,anderasestheoriginalparticle’sstate.Humanbeings

arejustlargecollectionsofparticles,sointheoryit shouldbepossible

toteleportthemtoo.Butthereareinsurmountabledifficulties.The

numberofparticlesinvolvedis over4 tredecillion– fourwith 42 zeros

afterit.There’snowaytohandlethatamountofdata quiteapartfrom

thetechnical

challengeofcreating

allthoseentangled

pairsofparticles.Eve

if it wasphysically

possible,the

philosopherDerek

Parfithasargued

thata teleported

copywouldn’tbe

thesameasthe

originalperson.

aytohandlethatamountofdata,quiteapartfrom

g

en

http://www.howitworksdaily.com

DID YOU KNOW? It would take 1he entire UK electricity grid a million years to power the teleportation of a single human

An exact copy of the particle being

teleported appears at the receiving end

How quantum

teleportation works

1

Teleportation’sorigins

Theword‘teleportation’wasn’t

formallyuseduntilthe20th

century,althoughtheconceptof

objectsdisappearingfromone

placeandappearingintheother

hasbeendocumentedsince1878.

2

Einsteincalled

entanglement“spooky”

Notbecausehefoundit scary– he

justdidn’tbelieveinit.Hesaid

“physicsshouldrepresenta reality

intimeandspace,freefrom

spookyactionata distance”.

3

TheAspectexperiment

Proofthatentanglementis real

cameintheearly1980switha

groundbreaking experimental

demonstration by French physicist

Alain Aspect.

4

Mainstream use

The word ‘teleportation’ was

first used in a serious scientific

context in 1993 in a theoretical

paper written by Charles Bennett

and his team.

5

Long-distance teleportation

In June 2017, Chinese scientists

teleported a quantum state from a

ground-based lab to a satellite in

orbit, 300 miles away.

TELEPORTATION

© Getty

Why is teleportation important?

At first sight, being able to copythequantumstateofa particlemaynotlookexciting

• but it’s hugely significant for theviabilityofquantumcomputers.Inplaceof
  electronic components that arealwaysinoneoftwostates,representingbinarydigit
  zero or one, these employ quantumparticlesthatcanbeinanysuperpositionofthese
  states. The result, called a ‘qubit’,makesquantumcomputingmuchmoreefficientat
  number-crunching tasks like code-breakingandequation-solving.
  There’s a catch though. Qubits,likeallquantumstates,aredestroyedbyany
  attempt to measure them. It’s herethatteleportationcomestotherescue,byallowin
  information to be extracted – andeventransmittedtodistantlocations– without
  disturbing the system. It’s an intrinsicallysecureprocess,too– becauseonceagain
  you can’t observe a quantum particlewithoutchangingitsstate.Tryingtoeavesdrop
  on a ‘teleported’ communicationwilldestroythemessage.

g

ts

e

ng

Conceptualillustrationof

single-atomqubits,shownin

red,ina quantumcomputer

© National Institute of Standards and Technology

Teleporting humans

Star Trek’s

transporter is a great

sci-fi gimmick, but

totally impractical in

the real world

© Getty

Symbolic representation of a pair of

quantum particles in an entangled state

© NASA

Photon Entangled

photons

Transformation

Classical

signal

Bell-state

analyser

SENDER RECEIVER

Sender

ThesenderhasparticleX

• tobeteleported– as
  wellasparticleA,onehalf
  ofanentangledpair.

pho

Entangledparticlepair

Thekeytoteleportationis thefactthatA andB,although

widelyseparated,arein a sharedquantumstate.

Resultofanalysis

Theanalyserequipment

transmitsa singlenumber

• notthefullquantumstate


• totheremotereceiver.

Receiver

Thereceiverhas

theotherentangled

particle,B,which

willbetransformed

intoa copyofX.

Quantumstateanalyser

ThesenderputsX,theparticletobe

teleported,intothisgadgetwiththeir

halfoftheentangledpair,A.

Makinga copy

Thereceiverusesthenumber

providedbytheanalysertotransform

particleB intoanexactcopyofX.