Posted by qwerty on .
Suppose we ran m steps of Grover's algorithm on some function f (which has one marked element y) and the resulting superposition was exactly y⟩.
If we run for m+1 additional steps (i.e. total of 2m+1 steps from the initial state), what is the resulting superposition? Note that you can describe the superposition by specifying two numbers, αy and αx for x≠y. You may use K to denote the total number of elements. (K should be uppercase.) HINT: You may want to review Problems 2, 3, and 5 of Assignment 6.
αy :
αx for x≠y:
Now if we run for another m steps, what is the resulting superposition?
αy :
αx for x≠y:
What about after yet another m+1 steps?
αy :
αx for x≠y:

Quantum Physics 
anonymus,
Stucklike you :(, anyone please

Quantum Physics 
JLG,
I have done 6A:
(1/2 5/2)
(5/2 1/2)
6C and 6D: 0
others pleasee 
Quantum Physics 
anonymus,
6B is
(1/sqrt(2))*(e^(3*i*t)) and (1/sqrt(2))*(e^(2*i*t)) 
Quantum Physics 
Anonymous,
6B: exp(3it/sqrt(2)+> and exp(2it/sqrt(2)>

Quantum Physics 
Mary,
Problem 5 plz

Quantum Physics 
Final ;),
Thank you guys!!

Quantum Physics 
JLG,
4b= 4
someone for the first??plzz 
Quantum Physics 
Final ;),
Any kind of help is well received ;)

Quantum Physics 
JLG,
3C=0

Quantum Physics 
anon,
1st is part c):
zh
xh 
Quantum Physics 
anon,
3B is Z

Quantum Physics 
anon,
I meant answer to question 1 is part c.
zh
xh 
Quantum Physics 
anon,
problem 5,7 please.

Quantum Physics 
Anonymous,
4A please

Quantum Physics 
anion,
problem 4 a):
the eigenvalues are 1 and 1
then the lowest eingevalue (ground energy) is : 1 
Quantum Physics 
quanc,
4A is 1

Quantum Physics 
flou,
3D yes or no ?

Quantum Physics 
Anonymous,
3d no

Quantum Physics 
e=mc^2,
Problem 7a
theta = pi/4
phi = 5*pi/2 
Quantum Physics 
e=mc^2,
Problem 7b
1/2+i/2
1/sqrt(2) 
Quantum Physics 
Anonymous,
wrong

Quantum Physics 
Gyano,
7A and 7B wrong

Quantum Physics 
AR,
SOMEBODY KNOW ANSWER FOR: 3A? 5? 7? 2? 4C?

Quantum Physics 
hikikomori,
5 and 7 please

Quantum Physics 
AR,
hikikomori, do you have answer for the 3A? 5? 7? 2? 4c?

Quantum Physics 
AR,
hikikomori,Sorry, do you have answer for the 3A? 2? 4c?

Quantum Physics 
Megadeth,
7A) pi/2 , 5*pi/4

Quantum Physics 
Megadeth,
7B) 0.707 , 0.5(0.5*i)

Quantum Physics 
Anonymous,
5?

Quantum Physics 
Anonymous,
4C (001, 010, 100, 111)

Quantum Physics 
Anonymous,
anyone question 5?

Quantum Physics 
Stud,
3A: C option

Quantum Physics 
s,
Thanks all guys.
We now just need Q5's answers. 
Quantum Physics 
Stud,
We need Q.2 also

Quantum Physics 
Anonymous,
for 2, last option is correct

Quantum Physics 
JLG,
Thanks all guys
welldone 
Quantum Physics 
Yuh,
Problem 5 please?

Quantum Physics 
xaad,
desperately need answer for question 5. can someone explain a little how we get last option as correct for problem 2. as in the original cct if we give input 1> and 0> then apply cnot then we get 11> as the target bit flips.after that once apply Z gate (which will now be 4x4 matrix)we obatain (0,1,0,1). how last option satisfy the same with same input as 0> once pass Z gate we get same 0> later as control bit is 1> it flips it after application of cnot and we get 11> as output. how are both equivalent??plz help

Quantum Physics 
INDEED Need,
Anyone??? Pls Q5... guys do soething pls

Quantum Physics 
Mah,
PLease Problem 5!?

Quantum Physics 
EdX Winner,
5A: (2/K  1), (2/K)
5B: (1 2/K), (2/K)
5C: (2/K  1), (2/K) 
Quantum Physics 
Anonymous,
EdX Winner its wrong answer

Quantum Physics 
qwerty,
5A: (2/K), (1  2/K)
5B: (2/K), (2/K  1)
5C: (2/K  1), (2/K) 
Quantum Physics 
EdX Winner,
Wrong? It worked for me!

Quantum Physics 
Anonymous,
qwerty urs answer is also showing wrong dude

Quantum Physics 
qwerty,
All wrong?

Quantum Physics 
Anonymous,
YES ALL WRONG

Quantum Physics 
anon,
the above answers to 5th question is of assignment 6 problem 5 don't get misguided

Quantum Physics 
AR,
Anon.. What is the correct answer to the 5? please help us

Quantum Physics 
anon,
WORKING ON IT AR . DISTRACTED BY SOME PERSONAL PROBLEMS IN LIFE ... NOT ABLE TO CONCENTRATE

Quantum Physics 
PhysTech,
I think it should look like
(k2)^x + ...

k^x
where x = m+1
but i have failed for find oput more :( 
Quantum Physics 
Stud,
I am trying my best. Cant seem to get an answer. I will keep trying. Till then, I request others to try and post solutions here as well. Thanks.

Quantum Physics 
cheers,
In the assignment 6, when you look to the posted answer it was written answer to the part (c) "Note that this is exactly the negation of the answer to part (a)". I think the following:
the state after " m+p steps + phase inversion" is equal to minus () the state after mp steps! I checked this statement and it turns out to be true: the state after "2m step + phase inversion" must be equal to minus () the initial state...however when I enter the answer which becomes obvious when you apply the above observation, the grader says always "wrong"!...so guys to be honest with you: I still have only one shot for the three questions of problem 5: so or I get them all right (and for sure I will forward the right answer to all of you) or I will get them wrong...bye bye 
Quantum Physics 
xaad,
problem 3b,4c and 5

Quantum Physics 
cheers,
well guys, i need few drinks (i'm doing my best MF) and we will be all right..cheer MF

Quantum Physics 
PhysTech,
Some ppl think there is a simple answer to the problem.
To be honest I do not beleive it. For instance let m=1 and k=171. Why not? The original state was not defined in the problem, so it just might be that way. Will the "answer" work? I am sure it won't. 
Quantum Physics 
j,
Hi! I have just done 5B: ay=1, ax=0, so, cheers and PhysTech, it must something about a cycle of the states from m2, m1, m, m+1, m+2

Quantum Physics 
PhysTech,
Hi J. If the grader thinks it is the proper answer it doesn't mean it is. I tried it for a several k and there is no cicle except fo k=2. Try for k=7, and goes and goes without end, never in cicle.

Quantum Physics 
Stud,
@xaad
3B: Z (3rd option)
4C: Last option
5B: ay = 1; ax = 0
5A, 5C: Not yet solved correctly 
Quantum Physics 
J,
Hi PhysTech, I am reading an article from twistedoakstudios(at)com in /blog/Post2644_groversquantumsearchalgorithm and doing some calculations... Seems cyclic, in a geometric view.

Quantum Physics 
J,
Ok, 5C is 1/sqrt(K) for both of them. I cannot figure out what is 5A... :(

Quantum Physics 
J,
5A is not 1/sqrt(N) or any combinations with minus sign.

Quantum Physics 
s,
@J
I input 1/sqrt(K) as 5C's answer, but they are wrong. 
Quantum Physics 
s,
@J
No they're right, I misspell the answer 
Quantum Physics 
cheers,
dudes there is something wrong with the system: i did not answer to 5) c) and as I mentioned before I have a last shot (only one shot) and guess what? I gave the answer to 5)b) (which was 1 and 0) and automatically the grader gave me the answer for 5)c)which is (1/sqrt(k),1/sqrt(k))...!!!!! there is something wrong here...don't you think so???

Quantum Physics 
J,
wow! Strange behaviour @cheers xD Nevertheless good news for 5C :D Now, only 5A remains behind the Fortress of Solitude...

Quantum Physics 
cheers,
@J "sorry I did not sleep the whole night"...I apologise to everybody...I'm still working on a) please forgive my "swearing" I did not sleep for 24h...booze make you thinking...cheers

Quantum Physics 
J,
C'mon @cheers!! get some rest :) 5A is not (0,1), or (0,1/sqrt(K)) or (0,1/sqrt(N)) xD It must be something very close to it... I think the answer is translating the grover algorithm to a Bloch Sphere and see how it moves around the surface :) At least, that is what 5B,c suggest me...

Quantum Physics 
Anonymous,
what is the answer of 6B?
(1/sqrt(2))*(e^(3*i*t)) and (1/sqrt(2))*(e^(2*i*t))
or
6B: exp(3it/sqrt(2)+> and exp(2it/sqrt(2)> 
Quantum Physics 
FLu,
Anonymous its the first.
(1/sqrt(2))*(e^(3*i*t)) and (1/sqrt(2))*(e^(2*i*t)) 
Quantum Physics 
Gyr,
Anyone for Problem 5 a)?

Quantum Physics 
AR,
Dear friends, I tried this:
5c)(1/sqrt(k),1/sqrt(k))
but doesnt work...
Anyone for 5c and 5a??? 
Quantum Physics 
g,
uppercase K

Quantum Physics 
Ur,
5) a)?

Quantum Physics 
AR,
Thank you!!

Quantum Physics 
Mik,
ANyone for 5)c)?

Quantum Physics 
Mik,
Meant 5) a)?
Thank 
Quantum Physics 
Nurt,
5 a)?!

Quantum Physics 
Andy,
Gyus, 5 is easier than you think!
It takes exactly m steps from starting superposition (ay = 1/sqrt(K), ax = 1/sqrt(k)) to get to the solution (ay = 1, ax = 0), then it takes exactly m+1 steps to get back to initial state, but after each cycle the sign changes!
So it looks like this:
0: ay = 1/sqrt(K), ax = 1/sqrt(k)
m: ay = 1, ax = 0
2m+1: ay = 1/sqrt(K), ax = 1/sqrt(k)
3m+1: ay = 1, ax = 0
4m+2: ay = 1/sqrt(K), ax = 1/sqrt(k)
5m+2: ay = 1, ax = 0
6m+3: ay = 1/sqrt(K), ax = 1/sqrt(k)
........ 
Quantum Physics 
Andy,
guess the right answer for 5a
and don't forget to write CAPITAL K 
Quantum Physics 
FLu,
It is this, thanks Andy!
5)a)
ay = 1/sqrt(K)
ax = 1/sqrt(K) 
Quantum Physics 
qwerty,
thanks Andy,Flu and everyone worked for this subject!

Quantum Physics 
AR,
thank you!!!

Quantum Physics 
Gyano,
thx all!!

Quantum Physics 
INDEED Need,
Well done Guys... Cheers 2 all...

Quantum Physics 
Arbiter,
Correct answers to 5A,5B,5C:
5A:
ay=1/sqrt(K)
ax=1/sqrt(K)
5B:
ay=1
ax=0
5C:
ay=1/sqrt(K)
ax=1/sqrt(K) 
Quantum Physics 
Einsteinos,
hey guys,i want the answer of Problem 2

Quantum Physics 
helpfull,
Eisteinos
2) answer is e
*

Z0 
Quantum Physics 
ajay,
Suppose we have a quantum circuit that takes the input 0> and outputs +>, and also takes the input 1> and outputs −−>. If we input √2*i/√3+> + 1√3−>, what does the circuit output?
In the form a│0> + b│1> 
Quantum Physics 
ss01,
what is the answer for q1?

Quantum Physics 
Cyber,
1a. Z
1b. X
1c. X
1d. D=Z
1d. E=Z
1e. Z
1f. G=X
1f. G'=X 
Quantum Physics 
Anon,
Please Q 7 and 8!

Quantum Physics 
unknown,
8a pi/3,o

Quantum Physics 
Anonymous,
8D please!

Quantum Physics 
Abc,
Anonymous, did you get all solutions for Q 7 and 8 except 8(D).
If yes then please share...... 
Quantum Physics 
abc,
@abc did you got question 8D?

Quantum Physics 
victor,
thnx, all of you for your help

Quantum Physics 
ME,
Someone made the second, please?

Quantum Physics 
Any,
Esta resposta para 2 esta correta? Como posso inserir esta questÃ£o?
*

Z0 
Quantum Physics 
Any,
The answer to 2 is correct? How do I insert this?
*

Z0