quantum architectures€¦ · classical vs. quantum sic element: 0 or 1 ts are independent ata may...
TRANSCRIPT
Qua
ntu
m
Qua
ntu
m
Arc
hit
ectu
res
Arc
hit
ectu
res
Jun
e 1,
200
5Ju
ne
1, 2
005
Com
pu
tin
g?
Com
pu
tin
g?
e of
com
putin
g d
evic
es th
at e
xhib
it qu
antu
e of
com
putin
g d
evic
es th
at e
xhib
it qu
antu
chan
ical
beh
avio
rch
anic
al b
ehav
ior
ehav
ior
of is
olat
ed io
ns
ehav
ior
of is
olat
ed io
ns
Bos
e B
ose --
Ein
stei
n co
nden
sate
in a
mag
net
ic w
ell
Ein
stei
n co
nden
sate
in a
mag
net
ic w
ell
hoto
n in
tera
ctio
ns
hoto
n in
tera
ctio
ns
ire
and
tran
sist
or in
tera
ctio
ns
in th
e n
ear
futu
reir
e an
d tr
ansi
stor
inte
ract
ion
s in
the
nea
r fu
ture
e co
mpu
ting
mod
el is
larg
ely
unex
plor
ed c
ompu
ting
mod
el is
larg
ely
unex
plor
ed
⊆⊆?
QP
?
QP
⊆⊆
? N
P?
NP
e us
age
mod
el is
stil
l bei
ng d
ebat
ed u
sag
e m
odel
is s
till b
eing
deb
ated
hy a
re A
rch
itec
ts I
nvo
lved
hy a
re A
rch
itec
ts I
nvo
lved
e kn
ow w
hat t
he
“kill
er a
pp”
will
be
e kn
ow w
hat t
he
“kill
er a
pp”
will
be
Err
or c
orre
ctio
n w
ill b
e >
99%
of t
he w
ork
Err
or c
orre
ctio
n w
ill b
e >
99%
of t
he w
ork
e ph
ysic
ists
don
’t kn
ow c
ompu
tatio
ne
phys
icis
ts d
on’t
know
com
puta
tion
“Don
’t w
orry
, it’s
pol
ynom
ial..
.”“D
on’t
wor
ry, i
t’s p
olyn
omia
l...”
e th
eori
sts
don’
t kno
w p
hysi
cse
theo
rist
s do
n’t k
now
phy
sics
“Sim
plify
the
prob
lem
by
rem
ovin
g co
mm
unic
atio
n...”
“Sim
plify
the
prob
lem
by
rem
ovin
g co
mm
unic
atio
n...”
sho
rt, a
rchi
tect
s ca
n be
the
real
ity c
hec
k s
hort
, arc
hite
cts
can
be th
e re
ality
ch
eck
Iden
tify
phys
ical
bou
nds
that
sup
erse
de
theo
retic
al o
nId
entif
y ph
ysic
al b
ound
s th
at s
uper
sed
e th
eore
tical
on
Det
erm
ine
wha
t asp
ects
of
com
puta
tion
will
be
the
mD
eter
min
e w
hat a
spec
ts o
f co
mpu
tatio
n w
ill b
e th
e m
och
alle
ngin
gch
alle
ngin
g
Ou
tlin
eO
utl
ine
hat m
akes
qu
antu
m d
iffer
ent?
hat m
akes
qu
antu
m d
iffer
ent?
Qu
antu
m b
itsQ
uan
tum
bits
Op
erat
ion
s an
d m
easu
rem
ent
Op
erat
ion
s an
d m
easu
rem
ent
Dec
oher
ence
Dec
oher
ence
hat w
ill a
qu
antu
m c
ompu
ter
look
like
hat w
ill a
qu
antu
m c
ompu
ter
look
like
uan
tum
arc
hite
ctur
e re
sear
ch a
t UW
uan
tum
arc
hite
ctur
e re
sear
ch a
t UW
Cur
rent
res
earc
h: S
imul
atio
nC
urre
nt r
esea
rch:
Sim
ulat
ion
Bui
ldin
g qu
antu
m w
ires
Bui
ldin
g qu
antu
m w
ires
Cla
ssic
al v
s. Q
uan
tum
Cla
ssic
al v
s. Q
uan
tum
sic
elem
ent:
0 o
r 1
sic
elem
ent:
0 o
r 1
ts a
re in
dep
end
ent
ts a
re in
dep
end
ent
ata
may
be
copi
ed
ata
may
be
copi
ed
des
troy
ed a
t will
des
troy
ed a
t will
ata
is s
tatic
ata
is s
tatic
nnB
its
are
cont
inuo
us
vaB
its
are
cont
inuo
us
vann
Bit
s m
ay b
e en
tang
led
Bit
s m
ay b
e en
tang
led
inte
rfer
ein
terf
ere
nnD
ata
may
not
be
copi
eD
ata
may
not
be
copi
enn
Op
erat
ions
mu
st b
e O
per
atio
ns m
ust
be
reve
rsib
lere
vers
ible
nnD
ata
Dat
a de
coh
eres
deco
her
esw
ith t
with
t
Qub
its
Qub
its :
Qu
antu
m B
its
: Q
uan
tum
Bit
s
and
an
d q
ubits
qubi
tsbo
th h
ave
two
stat
es:
0 an
both
hav
e tw
o st
ates
: 0
an
per
posi
tion:
p
erpo
sitio
n:
ubit
ubit
may
be
in b
oth
stat
es s
imul
tan
eous
lym
ay b
e in
bot
h st
ates
sim
ulta
neo
usly
ase:
ase:
ubit
ubit
may
hav
e a
neg
ativ
e qu
antit
y of
a s
tm
ay h
ave
a n
egat
ive
quan
tity
of a
st
uan
tum
Sta
tes
and
Mea
sure
men
uan
tum
Sta
tes
and
Mea
sure
men
e e qu
bit
qubi
t pro
babi
listic
ally
rep
rese
nts
two
stat
espr
obab
ilist
ical
ly r
epre
sent
s tw
o st
ates
a |0
> +
b |1
> a
|0>
+ b
|1>
ch a
dditi
onal
ch
add
ition
al q
uibi
tqu
ibit
doub
les
the
num
ber
of s
tado
uble
s th
e nu
mbe
r of
sta
a |0
0> +
b |
01>
+c |
10>
+ d
|11
>a
|00>
+ b
|01
> +c
|10
> +
d |
11>
easu
rem
ent s
end
s a
easu
rem
ent s
end
s a
qubi
tqu
bit i
nto
a cl
assi
cal s
tat
into
a c
lass
ical
sta
tis
may
alte
r the
sta
tes
of o
ther
is
may
alte
r the
sta
tes
of o
ther
qub
itsqu
bits
a |0
0> +
b |
11>
(E
PR
sta
te)
a |0
0> +
b |
11>
(E
PR
sta
te)
easu
rem
ent
and
Cop
y P
rote
ctio
easu
rem
ent
and
Cop
y P
rote
ctio
uan
tum
dat
a ca
nnot
be
copi
edu
antu
m d
ata
cann
ot b
e co
pied
Cop
ying
invo
lves
a r
ead
and
a w
rite
Cop
ying
invo
lves
a r
ead
and
a w
rite
“Rea
ding
” d
estr
oys
the
stat
e“R
eadi
ng”
des
troy
s th
e st
ate
uan
tum
dat
a ca
n be
tran
sfer
red
uan
tum
dat
a ca
n be
tran
sfer
red
On
e O
ne
qubi
tqu
bit
can
swap
its
stat
e w
ith a
noth
erca
n sw
ap it
s st
ate
with
ano
ther
Qu
antu
m s
tate
can
be
“tel
epor
ted”
ove
r in
finite
Q
uan
tum
sta
te c
an b
e “t
elep
orte
d” o
ver
infin
ite
dist
ance
(bu
t th
e se
nder
lose
s th
e d
ata)
dist
ance
(bu
t th
e se
nder
lose
s th
e d
ata)
any
quan
tum
alg
orith
ms
are
prob
abili
stic
an
y qu
antu
m a
lgor
ithm
s ar
e pr
obab
ilist
ic
d in
volv
e it
erat
ion
d in
volv
e it
erat
ion
Oth
er O
per
atio
ns
Oth
er O
per
atio
ns
easu
rem
ent:
the
only
irre
vers
ible
op
erat
iea
sure
men
t: th
e on
ly ir
reve
rsib
le o
per
ati
l oth
er o
per
atio
ns a
re r
ever
sibl
el o
ther
op
erat
ions
are
rev
ersi
ble
2nd
Law
: R
ever
sibl
e op
erat
ion
s co
nse
rve
ener
2nd
Law
: R
ever
sibl
e op
erat
ion
s co
nse
rve
ener
“Not
” is
rev
ersi
ble
“Not
” is
rev
ersi
ble
“And
” an
d “O
r” a
re n
ot r
ever
sibl
e“A
nd”
and
“Or”
are
not
rev
ersi
ble
ost “
trad
ition
al”
oper
atio
ns
mu
st p
rodu
ce
ost “
trad
ition
al”
oper
atio
ns
mu
st p
rodu
ce
ditio
nal
out
put
ditio
nal
out
put
How
do
you
mak
e “+
” re
vers
ible
?H
ow d
o yo
u m
ake
“+”
reve
rsib
le?
Scr
atch
bits
mu
st b
e pr
otec
ted
Scr
atch
bits
mu
st b
e pr
otec
ted
Noi
se:
N
oise
: D
eco
her
ence
Dec
oh
eren
ce
eore
tical
sys
tem
s ar
e “c
lose
d”eo
retic
al s
yste
ms
are
“clo
sed”
No
ener
gy m
ay e
nter
the
syst
em u
nles
s ex
plic
itly
No
ener
gy m
ay e
nter
the
syst
em u
nles
s ex
plic
itly
intr
odu
ced
intr
odu
ced
al s
yste
ms
can’
t be
com
plet
ely
isol
ated
al s
yste
ms
can’
t be
com
plet
ely
isol
ated
Per
form
ing
an o
p ad
ds
“noi
se”
to a
P
erfo
rmin
g an
op
add
s “n
oise
” to
a q
ubit
qubi
tO
ver
time,
O
ver
time,
qub
itsqu
bits
will
sim
ply
“w
ill s
impl
y “ d
ecoh
ere
dec
oher
e ””A
t hig
her t
emp
erat
ures
(hi
gher
ene
rgy)
, A
t hig
her t
emp
erat
ures
(hi
gher
ene
rgy)
, dec
oher
ence
dec
oher
ence
occu
rs m
ore
quic
kly
occu
rs m
ore
quic
kly
e w
ill n
eed
mas
sive
coo
ling
syst
ems
e w
ill n
eed
mas
sive
coo
ling
syst
ems
y u
sabl
e qu
antu
m s
yste
m w
ill r
equi
re e
rror
y
usa
ble
quan
tum
sys
tem
will
req
uire
err
or
rror
Cor
rect
ion
is
Cru
cial
rror
Cor
rect
ion
is
Cru
cial
ror
corr
ectin
g co
des
are
ava
ilabl
ero
r co
rrec
ting
cod
es a
re a
vaila
ble
Op
erat
ion
s ex
ist f
or c
ompu
ting
on e
ncod
ed d
atO
per
atio
ns
exis
t for
com
putin
g on
enc
oded
dat
aSi
nce
Si
nce
qub
itsqu
bits
cann
ot b
e re
ad, a
n er
ror
corr
ectio
nca
nnot
be
read
, an
erro
r co
rrec
tion
rout
ine
man
ipul
ates
the
cod
ed b
its to
fix
erro
rsro
utin
e m
anip
ulat
es th
e co
ded
bits
to fi
x er
rors
ror
corr
ectio
n m
ust
ofte
n b
e ap
plie
d ro
r co
rrec
tion
mu
st o
ften
be
appl
ied
curs
ivel
y to
err
or c
orre
ctio
n ro
utin
escu
rsiv
ely
to e
rror
cor
rect
ion
rout
ines
e T
hres
hold
The
orem
e T
hres
hold
The
orem
An
erro
r rat
e of
10
An
erro
r rat
e of
10-- 44
per
op c
an b
e to
lera
ted
per
op c
an b
e to
lera
ted
This
err
or r
ate
requ
ires
nea
rly
cont
inuo
us
erro
r Th
is e
rror
rat
e re
quir
es n
earl
y co
ntin
uou
s er
ror
corr
ectio
nco
rrec
tion
To
Su
mm
ariz
e...
To
Su
mm
ariz
e...
uan
tum
bits
are
aw
esom
eu
antu
m b
its a
re a
wes
ome
...ex
cept
that
no
one
has
real
ly d
one
anyt
hing
...
exce
pt th
at n
o on
e ha
s re
ally
don
e an
ythi
ng
amaz
ing
with
them
(yet
)am
azin
g w
ith th
em (y
et)
…be
cau
se m
easu
rem
ent r
eally
hur
ts…
beca
use
mea
sure
men
t rea
lly h
urts
orin
g an
d m
ovin
g d
ata
will
be
diffi
cult
orin
g an
d m
ovin
g d
ata
will
be
diffi
cult
Dec
oher
ence
Dec
oher
ence
limits
sto
rage
and
tran
sit t
ime
limits
sto
rage
and
tran
sit t
ime
e kn
ow w
hat q
uan
tum
com
pute
rs w
ill d
oe
know
wha
t qu
antu
m c
ompu
ters
will
do
Err
or c
orre
ctin
g...a
ll th
e tim
eE
rror
cor
rect
ing.
..all
the
time
rfor
min
g co
mpu
tatio
n in
the
pres
ence
of
rfor
min
g co
mpu
tatio
n in
the
pres
ence
of
Ou
tlin
eO
utl
ine
hat m
akes
qu
antu
m d
iffer
ent?
hat m
akes
qu
antu
m d
iffer
ent?
Qu
antu
m b
itsQ
uan
tum
bits
Op
erat
ion
s an
d m
easu
rem
ent
Op
erat
ion
s an
d m
easu
rem
ent
Dec
oher
ence
Dec
oher
ence
hat w
ill a
qu
antu
m c
ompu
ter
look
like
hat w
ill a
qu
antu
m c
ompu
ter
look
like
uan
tum
arc
hite
ctur
e re
sear
ch a
t UW
uan
tum
arc
hite
ctur
e re
sear
ch a
t UW
Cur
rent
res
earc
h: S
imul
atio
nC
urre
nt r
esea
rch:
Sim
ulat
ion
Bui
ldin
g qu
antu
m w
ires
Bui
ldin
g qu
antu
m w
ires
Pic
k a
Tec
hn
olog
yP
ick
a T
ech
nol
ogy
hat d
evic
e te
chno
logy
will
be
use
d?
hat d
evic
e te
chno
logy
will
be
use
d?
Who
kno
ws.
..W
ho k
now
s...
evel
op fi
rst o
rder
ass
um
ptio
ns
evel
op fi
rst o
rder
ass
um
ptio
ns
Cla
ssic
al c
ontr
ol o
f qua
ntum
gat
esC
lass
ical
con
trol
of q
uant
um g
ates
Silic
on to
inte
rfac
e an
d co
ntro
lSi
licon
to in
terf
ace
and
cont
rol
nnPr
ovid
es r
ough
siz
e co
nst
rain
tsPr
ovid
es r
ough
siz
e co
nst
rain
ts
Indi
vidu
al c
ontr
ol o
f qu
antu
m b
itsIn
divi
dual
con
trol
of q
uan
tum
bits
ck a
like
ly te
chno
logy
that
fits
ck a
like
ly te
chno
logy
that
fits
For
exam
ple,
ion
trap
sFo
r ex
ampl
e, io
n tr
aps
Con
sid
er B
uild
ing
Blo
cks
onsi
der
Bui
ldin
g B
lock
s
Proc
esso
r: C
ompu
tatio
nPr
oces
sor:
Com
puta
tion
Sev
eral
set
s of
uni
vers
al g
ates
exi
stS
ever
al s
ets
of u
nive
rsal
gat
es e
xist
Diff
eren
t dev
ice
tech
nolo
gies
can
mor
e ea
sily
impl
emD
iffer
ent d
evic
e te
chno
logi
es c
an m
ore
easi
ly im
plem
som
e ga
tes
than
oth
ers
som
e ga
tes
than
oth
ers
Mea
sure
men
t an
d “z
ero”
cre
atio
n is
als
o im
port
ant
Mea
sure
men
t an
d “z
ero”
cre
atio
n is
als
o im
port
ant
emor
y: S
tora
ge
emor
y: S
tora
ge
Stor
age
is d
iffic
ult b
ecau
se o
f St
orag
e is
diff
icul
t bec
ause
of
dec
oher
ence
dec
oher
ence
Con
stan
t err
or c
orre
ctio
n m
ay b
e p
erfo
rmed
C
onst
ant e
rror
cor
rect
ion
may
be
per
form
ed
nnD
ecoh
eren
ceD
ecoh
eren
ce-- f
ree
subs
pac
es a
re b
eing
res
earc
hed
free
sub
spac
es a
re b
eing
res
earc
hed
Hen
ce, m
emor
y lo
oks
a lo
t lik
e th
e pr
oces
sor
Hen
ce, m
emor
y lo
oks
a lo
t lik
e th
e pr
oces
sor
Inte
rcon
nec
t: C
omm
unic
atio
n In
terc
onn
ect:
Com
mun
icat
ion
reg
erre
ger
-- Sti
ckle
s an
d
Sti
ckle
s an
d B
alen
sief
erB
alen
sief
er
e co
mpu
ter i
s a
grid
of t
rap
s an
d w
ires
e co
mpu
ter i
s a
grid
of t
rap
s an
d w
ires
ch tr
ap h
as a
flex
ible
gat
e th
at c
an p
erfo
rm
ch tr
ap h
as a
flex
ible
gat
e th
at c
an p
erfo
rm
easu
rem
ent o
r a
quan
tum
op
easu
rem
ent o
r a
quan
tum
op
mm
unic
atio
n is
per
form
ed b
y m
ovin
g io
ns
mm
unic
atio
n is
per
form
ed b
y m
ovin
g io
ns
Ou
tlin
eO
utl
ine
hat m
akes
qu
antu
m d
iffer
ent?
hat m
akes
qu
antu
m d
iffer
ent?
Qu
antu
m b
itsQ
uan
tum
bits
Op
erat
ion
s an
d m
easu
rem
ent
Op
erat
ion
s an
d m
easu
rem
ent
Dec
oher
ence
Dec
oher
ence
hat w
ill a
qu
antu
m c
ompu
ter
look
like
hat w
ill a
qu
antu
m c
ompu
ter
look
like
uan
tum
arc
hite
ctur
e re
sear
ch a
t UW
uan
tum
arc
hite
ctur
e re
sear
ch a
t UW
Cur
rent
res
earc
h: S
imul
atio
nC
urre
nt r
esea
rch:
Sim
ulat
ion
Bui
ldin
g qu
antu
m w
ires
Bui
ldin
g qu
antu
m w
ires
Rep
rese
ntin
g qu
antu
m a
lgor
ithm
sR
epre
sent
ing
quan
tum
alg
orith
ms
mul
atin
g Q
uan
tum
Com
pu
teul
atin
g Q
uan
tum
Com
pu
te
nt w
ork
by
nt w
ork
by K
rege
rK
rege
r --St
ickl
es,
Stic
kles
, B
alen
sief
erB
alen
sief
er, a
nd O
, and
O
com
pare
arc
hite
ctur
es, p
erfo
rman
ce d
ata
is n
com
pare
arc
hite
ctur
es, p
erfo
rman
ce d
ata
is n
ulat
ion
is th
e on
ly c
hoic
eul
atio
n is
the
only
cho
ice
Fully
” si
mul
atin
g a
quan
tum
sys
tem
take
s ex
pone
ntia
lFu
lly”
sim
ulat
ing
a qu
antu
m s
yste
m ta
kes
expo
nent
ial
y m
odel
ing
only
rel
iabi
lity,
can
be
don
e in
line
ar ti
me
y m
odel
ing
only
rel
iabi
lity,
can
be
don
e in
line
ar ti
me
e S
imul
atio
n In
fras
tru
ctu
e S
imul
atio
n In
fras
tru
ctu
r
n er
ror
corr
ectio
n co
mpi
ler
err
or c
orre
ctio
n co
mpi
ler
Tak
es a
qu
antu
m a
lgor
ithm
for
one
spec
ific
inpu
Tak
es a
qu
antu
m a
lgor
ithm
for
one
spec
ific
inpu
Prod
uce
s a
faul
t tol
eran
t ver
sion
of t
he a
lgor
ithm
Prod
uce
s a
faul
t tol
eran
t ver
sion
of t
he a
lgor
ithm
dev
ice
sche
dule
rd
evic
e sc
hedu
ler
Tak
es a
pro
gram
and
an
arch
itect
ure
Tak
es a
pro
gram
and
an
arch
itect
ure
Pro
duce
s a
stat
ic o
pera
tion
and
com
mun
icat
ion
Pro
duce
s a
stat
ic o
pera
tion
and
com
mun
icat
ion
sch
edul
esc
hed
ule
relia
bilit
y si
mul
ator
relia
bilit
y si
mul
ator
Tak
es a
sch
edul
ed a
pplic
atio
n an
d a
rchi
tect
ure
Tak
es a
sch
edul
ed a
pplic
atio
n an
d a
rchi
tect
ure
Prod
uce
s p
erfo
rman
ce a
nd re
liabi
lity
met
rics
Prod
uce
s p
erfo
rman
ce a
nd re
liabi
lity
met
rics
Pre
lim
inar
y R
esu
lts
Pre
lim
inar
y R
esu
lts
ror
corr
ectio
n is
less
eff
ectiv
e th
an w
e as
sum
ror
corr
ectio
n is
less
eff
ectiv
e th
an w
e as
sum
Cor
rect
ing
erro
rs r
equi
res
that
bits
be
mov
edC
orre
ctin
g er
rors
req
uire
s th
at b
its b
e m
oved
e T
hres
hold
Th
eore
m is
opt
imis
tice
Thr
esho
ld T
heo
rem
is o
ptim
istic
Rea
listic
exe
cutio
n co
nst
rain
ts (
com
mun
icat
ion)
lim
it R
ealis
tic e
xecu
tion
con
stra
ints
(co
mm
unic
atio
n) li
mit
acce
ptab
le e
rror
rat
eac
cept
able
err
or r
ate
The
real
istic
thre
shol
d is
four
ord
ers
of m
agni
tud
e w
oTh
e re
alis
tic th
resh
old
is fo
ur o
rder
s of
mag
nitu
de
wo
antu
m c
ompu
ter
size
will
be
limite
d b
y th
e er
antu
m c
ompu
ter
size
will
be
limite
d b
y th
e er
te o
f the
und
erly
ing
tech
nolo
gyte
of t
he u
nder
lyin
g te
chno
logy
The
furt
her
bits
hav
e to
mov
e, th
e lo
wer
the
rate
has
Th
e fu
rthe
r bi
ts h
ave
to m
ove,
the
low
er th
e ra
te h
as t
bebe
ildi
ng
a Q
uan
tum
Wir
e (O
ski
ildi
ng
a Q
uan
tum
Wir
e (O
ski
get t
echn
olog
y is
Kan
e’s
silic
on io
nge
t tec
hnol
ogy
is K
ane’
s si
licon
ion
-- tratra
ons
are
embe
dded
into
sili
con
trap
son
s ar
e em
bedd
ed in
to s
ilico
n tr
aps
••Sp
in o
f 31P
hol
ds
quan
tum
sta
teSp
in o
f 31P
hol
ds
quan
tum
sta
te••
Ion
s sp
aced
Io
ns
spac
ed ≤≤
20nm
apa
rt fo
r qu
antu
m e
ffec
t to
o20
nm a
part
for
quan
tum
eff
ect t
o o
••≤≤
1.5K
elvi
n fo
r re
ason
able
coh
eren
ce ti
me
1.5K
elvi
n fo
r re
ason
able
coh
eren
ce ti
me
ocal
mag
net
ic fi
eld
arbi
trat
es g
ates
ocal
mag
net
ic fi
eld
arbi
trat
es g
ates
••C
ontr
olle
d b
y “c
lass
ical
” pi
nsC
ontr
olle
d b
y “c
lass
ical
” pi
ns••
Driv
en b
y hi
gh fr
equ
ency
(10
Driv
en b
y hi
gh fr
equ
ency
(10
-- 100
Mhz
) cl
ock
100M
hz)
cloc
k••
Gat
ed b
y “l
ower
” fr
equ
ency
(0.
01
Gat
ed b
y “l
ower
” fr
equ
ency
(0.
01 ––
10M
hz)
cloc
k10
Mhz
) cl
ock
A
A S
hor
tS
hor
tQ
uan
tum
Wir
eQ
uan
tum
Wir
e
nst
ruct
ed fr
om s
wap
gat
esn
stru
cted
from
sw
ap g
ates
Unl
ess
the
part
icle
tha
t ho
lds
the
quan
tum
sta
te
phys
ical
ly m
oves
, the
info
rmat
ion
�flo
ws� i
n di
scre
te
step
s fr
om p
arti
cle
to p
arti
cle.
Each
ste
p re
quir
es 3
qua
ntum
co
ntro
lled-
not
oper
atio
ns,
effe
ctiv
ely
perf
orm
ing
a �s
wap�
of
the
quan
tum
sta
tes.
rchi
tect
ure
of
a L
ong
Wir
rchi
tect
ure
of
a L
ong
Wir
e
EPR
Gene
rato
r
TeleporationUnit
TeleporationUnit
Entr
opy
Exch
ange
Puri
fica
tion
Code
dTe
le-
Port
atio
n
Clas
sica
l con
trol
cha
nnel
Qua
ntum
EPR
cha
nnel
R ch
anne
l
Tw
o P
oss
ible
Wir
esT
wo
Po
ssib
le W
ires
ort r
ange
: sw
appi
ngor
t ran
ge: s
wap
ping
-- cha
nnel
chan
nel
“Pitc
h m
atch
ing”
cau
ses
stru
ctur
al c
once
rns
“Pitc
h m
atch
ing”
cau
ses
stru
ctur
al c
once
rns
nnQ
ubits
Qub
itsar
e 20
nm a
par
t, so
con
trol
is li
mite
d to
5nm
are
20nm
ap
art,
so c
ontr
ol is
lim
ited
to 5
nmnn
@ 1
.5 K
elvi
n, c
anno
t driv
e an
AC
cur
rent
@ 1
.5 K
elvi
n, c
anno
t driv
e an
AC
cur
rent
nnO
ther
dim
ensi
ons
mu
st b
e in
crea
sed
to >
100
nmO
ther
dim
ensi
ons
mu
st b
e in
crea
sed
to >
100
nm
Len
gth
is li
mite
d du
e to
L
engt
h is
lim
ited
due
to d
ecoh
eren
ced
ecoh
eren
ce
ng ra
nge:
tel
epor
tatio
nng
rang
e: t
elep
orta
tion --
chan
nel
chan
nel
Len
gth
is a
rbitr
ary
Len
gth
is a
rbitr
ary
Man
y ad
ditio
nal s
tru
ctur
es a
re r
equi
red
Man
y ad
ditio
nal s
tru
ctur
es a
re r
equi
red
Ban
dwid
th is
con
stra
ined
by
EP
R p
air
prod
uct
ioB
andw
idth
is c
onst
rain
ed b
y E
PR
pai
r pr
odu
ctio
pre
sen
tin
g Q
uan
tum
Com
pu
tati
rese
nti
ng
Qu
antu
m C
omp
uta
ti
lop
an a
ltern
ativ
e no
tatio
n fo
r qu
antu
m c
ompu
ting
lop
an a
ltern
ativ
e no
tatio
n fo
r qu
antu
m c
ompu
ting
pres
enta
tion:
dea
ling
with
gro
ups
of b
its is
ha
pres
enta
tion:
dea
ling
with
gro
ups
of b
its is
ha
nsu
re o
per
atio
ns a
re in
sen
sitiv
e to
sta
te s
pac
e si
zen
sure
op
erat
ions
are
inse
nsi
tive
to s
tate
sp
ace
size
trod
uce
sho
rtha
nd fo
r co
mm
on e
ntan
gled
sta
tes
trod
uce
sho
rtha
nd fo
r co
mm
on e
ntan
gled
sta
tes
acili
tate
com
puta
tion
on la
rge,
hig
hly
enta
ngle
d s
tate
sac
ilita
te c
ompu
tatio
n on
larg
e, h
ighl
y en
tang
led
sta
tes
ason
ing:
int
eres
ting
stat
es a
re d
iffic
ult t
o id
enas
onin
g: i
nter
estin
g st
ates
are
diff
icul
t to
iden
entif
y qu
antu
m p
rop
ertie
s ex
plic
itly
entif
y qu
antu
m p
rop
ertie
s ex
plic
itly
efin
e op
erat
ions
by
the
quan
tum
pro
per
ties
they
indu
cef
ine
oper
atio
ns b
y th
e qu
antu
m p
rop
ertie
s th
ey in
duc
avor
loca
l tra
nsf
orm
atio
ns o
ver
glob
al o
nes
avor
loca
l tra
nsf
orm
atio
ns o
ver
glob
al o
nes
An
Exa
mpl
e: E
PR
Pai
rsA
n E
xam
ple:
EP
R P
airs
atri
x no
tatio
n:H
(x)→
x0:x
0+
x1||
x1:x
0
CN
ot(x
,y)→
x0:x
0y
||x1
:x
qubi
t p ⇒
p0
qubi
t q ⇒
q0
H(p
)on
p0⇒
p0+
p1
CN
ot(p
,q)
on(p
0+
p1)q
0
=
=
⊗
=
−
001
21101
211
0
00
00
0101
2101
01,
11
2101
1101
In th
e al
gebr
a:
Th
e H
igh
Ord
er B
its
Th
e H
igh
Ord
er B
its
uan
tum
arc
hite
ctur
e is
a w
ide
uan
tum
arc
hite
ctur
e is
a w
ide --
open
fiel
dop
en fi
eld
We
can’
t eve
n ag
ree
how
to b
uild
wire
s!W
e ca
n’t e
ven
agre
e ho
w to
bui
ld w
ires!
chite
cts
have
an
impo
rtan
t rol
e ch
itect
s ha
ve a
n im
port
ant r
ole
We
act
as in
term
edia
ries
betw
een
the
phys
icis
tW
e ac
t as
inte
rmed
iarie
s be
twee
n th
e ph
ysic
ist
and
alg
orith
m d
esig
ners
and
alg
orith
m d
esig
ners
you
know
how
to d
o er
ror
corr
ectio
n w
ell,
you
know
how
to d
o er
ror
corr
ectio
n w
ell,
u co
uld
beco
me
fam
ous
u co
uld
beco
me
fam
ous