Transformation of a bell state

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I am relatively new and interested in quantum computing.
Specifically, I am interested in transforming an equation that I found on Wikipedia. But I did not quite understand the transformation.



$ frac1sqrt2(left|0right>_xleft|0right>_y-left|1right>_xleft|1right>_y) = frac1sqrt2(|+rangle_x|-rangle_y+|-rangle_x|+rangle_y) $



My idea is so far to use Hadamard transform for the two qubits:



$ frac1sqrt2(H(left|0right>_xleft|0right>_y)-H(left|1right>_xleft|1right>_y)) $



I have used the Hadamard transformation and now come to this:



$ = frac1sqrt2(frac12[(left|00right>+left|10right>+left|01right>+left|11right>) -(left|00right>-left|10right>-left|01right>+left|11right>)]) $



If I simplify that a bit now then I have that as a result:



$ = frac1sqrt2(left|1_x0_yright>+left|0_x1_yright>) $



But the result looks different now than the equation I wrote down at the beginning:



$ = frac1sqrt2(left|1_x0_yright>+left|0_x1_yright>) = frac1sqrt2(|+rangle_x|-rangle_y+|-rangle_x|+rangle_y) $



I do not know if the forming is allowed that way. If somebody knows how the transformation of the equation works, so that I get what I wrote in the beginning, I would be very happy if somebody could explain it!



I hope that my question is understandable :)










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P_Gate is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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    up vote
    2
    down vote

    favorite












    I am relatively new and interested in quantum computing.
    Specifically, I am interested in transforming an equation that I found on Wikipedia. But I did not quite understand the transformation.



    $ frac1sqrt2(left|0right>_xleft|0right>_y-left|1right>_xleft|1right>_y) = frac1sqrt2(|+rangle_x|-rangle_y+|-rangle_x|+rangle_y) $



    My idea is so far to use Hadamard transform for the two qubits:



    $ frac1sqrt2(H(left|0right>_xleft|0right>_y)-H(left|1right>_xleft|1right>_y)) $



    I have used the Hadamard transformation and now come to this:



    $ = frac1sqrt2(frac12[(left|00right>+left|10right>+left|01right>+left|11right>) -(left|00right>-left|10right>-left|01right>+left|11right>)]) $



    If I simplify that a bit now then I have that as a result:



    $ = frac1sqrt2(left|1_x0_yright>+left|0_x1_yright>) $



    But the result looks different now than the equation I wrote down at the beginning:



    $ = frac1sqrt2(left|1_x0_yright>+left|0_x1_yright>) = frac1sqrt2(|+rangle_x|-rangle_y+|-rangle_x|+rangle_y) $



    I do not know if the forming is allowed that way. If somebody knows how the transformation of the equation works, so that I get what I wrote in the beginning, I would be very happy if somebody could explain it!



    I hope that my question is understandable :)










    share|improve this question







    New contributor




    P_Gate is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
    Check out our Code of Conduct.





















      up vote
      2
      down vote

      favorite









      up vote
      2
      down vote

      favorite











      I am relatively new and interested in quantum computing.
      Specifically, I am interested in transforming an equation that I found on Wikipedia. But I did not quite understand the transformation.



      $ frac1sqrt2(left|0right>_xleft|0right>_y-left|1right>_xleft|1right>_y) = frac1sqrt2(|+rangle_x|-rangle_y+|-rangle_x|+rangle_y) $



      My idea is so far to use Hadamard transform for the two qubits:



      $ frac1sqrt2(H(left|0right>_xleft|0right>_y)-H(left|1right>_xleft|1right>_y)) $



      I have used the Hadamard transformation and now come to this:



      $ = frac1sqrt2(frac12[(left|00right>+left|10right>+left|01right>+left|11right>) -(left|00right>-left|10right>-left|01right>+left|11right>)]) $



      If I simplify that a bit now then I have that as a result:



      $ = frac1sqrt2(left|1_x0_yright>+left|0_x1_yright>) $



      But the result looks different now than the equation I wrote down at the beginning:



      $ = frac1sqrt2(left|1_x0_yright>+left|0_x1_yright>) = frac1sqrt2(|+rangle_x|-rangle_y+|-rangle_x|+rangle_y) $



      I do not know if the forming is allowed that way. If somebody knows how the transformation of the equation works, so that I get what I wrote in the beginning, I would be very happy if somebody could explain it!



      I hope that my question is understandable :)










      share|improve this question







      New contributor




      P_Gate is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      I am relatively new and interested in quantum computing.
      Specifically, I am interested in transforming an equation that I found on Wikipedia. But I did not quite understand the transformation.



      $ frac1sqrt2(left|0right>_xleft|0right>_y-left|1right>_xleft|1right>_y) = frac1sqrt2(|+rangle_x|-rangle_y+|-rangle_x|+rangle_y) $



      My idea is so far to use Hadamard transform for the two qubits:



      $ frac1sqrt2(H(left|0right>_xleft|0right>_y)-H(left|1right>_xleft|1right>_y)) $



      I have used the Hadamard transformation and now come to this:



      $ = frac1sqrt2(frac12[(left|00right>+left|10right>+left|01right>+left|11right>) -(left|00right>-left|10right>-left|01right>+left|11right>)]) $



      If I simplify that a bit now then I have that as a result:



      $ = frac1sqrt2(left|1_x0_yright>+left|0_x1_yright>) $



      But the result looks different now than the equation I wrote down at the beginning:



      $ = frac1sqrt2(left|1_x0_yright>+left|0_x1_yright>) = frac1sqrt2(|+rangle_x|-rangle_y+|-rangle_x|+rangle_y) $



      I do not know if the forming is allowed that way. If somebody knows how the transformation of the equation works, so that I get what I wrote in the beginning, I would be very happy if somebody could explain it!



      I hope that my question is understandable :)







      quantum-gate qubit qubit-state






      share|improve this question







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      P_Gate is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      share|improve this question







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      P_Gate is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.









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      asked 38 mins ago









      P_Gate

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      New contributor





      P_Gate is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






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      Check out our Code of Conduct.




















          2 Answers
          2






          active

          oldest

          votes

















          up vote
          2
          down vote













          You've started wanting to talk about
          $$
          (|00rangle-|11rangle)/sqrt2,
          $$

          but you've then gone ahead and calculated
          $$
          (Hotimes H)cdot(|00rangle-|11rangle)/sqrt2.
          $$

          You should not expect these to be equal.



          On the other hand, the calculation that you've done is sensible if you understand what you're doing. What you actually want to see, in order to verify your original statement is that
          $$
          (Hotimes H)cdot(|00rangle-|11rangle)/sqrt2=(Hotimes H)cdot(|+-rangle+|-+rangle)/sqrt2.
          $$

          You've already calculated the left-hand side. The calculation on the right-hand side is, I suspect, the whole reason why you've chosen to apply the Hadamard transform - you know that the Hadamard converts $|+rangle$ to $|0rangle$, and $|-rangle$ to $|1rangle$. So, you can immediately read that
          $$
          (Hotimes H)cdot(|+-rangle+|-+rangle)/sqrt2=(|01rangle+|10rangle)/sqrt2,
          $$

          so you can see that the left-hand side is equal to the right-hand side, as desired.






          share|improve this answer




















          • Ok, so if I understand that correctly, I would just have to apply the Hadamard transformation on the right as well, and I would have achieved what I wanted to show?
            – P_Gate
            26 mins ago










          • @P_Gate Yes, that's correct. It's like starting with a statement 1=1. If you multiply just one side by 5, the statement becomes untrue; you have to do it to both sides.
            – DaftWullie
            18 mins ago










          • Thanks for the clarification. I was just too stupid. It is an equation, i. I also have to do what I do on the left side on the right side. Stupid to forget something like that. :) Sorry that I can not upvote your answer :( (not enough rep)
            – P_Gate
            16 mins ago


















          up vote
          1
          down vote













          You are not proving the equality in a correct way. By multiplying by the Hadamard matrix, you are changing the state you are trying to calculate, not demonstrating the equality you want to prove.$defket#1lvert#1rangle$



          In order to prove what you state at the beginning of the question, I would use the facts that $$
          ket+ =frac1sqrt2bigl(ket0 + ket1bigr), qquadket-=frac1sqrt2bigl(ket0 - ket1bigr),$$

          and then develop the equality in the inverse order. Consequently:
          $$
          beginalignat2
          frac1sqrt2&bigl(ket+_x ket-_y - ket-_x ket+_ybigr)mspace-128mu
          \[1ex]=;&
          frac1sqrt2Bigl(frac12bigl(&&ket0_x+ket1_xbigr)bigl(ket0_y-ket1_ybigr)+bigl(ket0_x-ket1_xbigr)bigl(ket0_y+ket1_ybigr)Bigr)
          \[1ex]=;&
          frac1sqrt2Bigl(frac12bigl(&&ket0_xket0_y+ket1_xket-_y-ket0_xket1_y-ket1_xket1_y
          \[-1ex]&&&+ket0_xket0_y+ket0_xket1_y-ket1_xket0_y-ket1_xket1_ybigr)Bigr)
          \=;&
          frac1sqrt2bigl(ket0_xket0_y - ket1_xket1_ybigr).mspace-128mu
          endalignat
          $$



          And so you prove the equality you were trying to solve at the beginning of the question.






          share|improve this answer


















          • 1




            Thanks, your answer is also helpful for me! I would upvote but I have not enough reputation :(
            – P_Gate
            15 mins ago










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          2 Answers
          2






          active

          oldest

          votes








          2 Answers
          2






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes








          up vote
          2
          down vote













          You've started wanting to talk about
          $$
          (|00rangle-|11rangle)/sqrt2,
          $$

          but you've then gone ahead and calculated
          $$
          (Hotimes H)cdot(|00rangle-|11rangle)/sqrt2.
          $$

          You should not expect these to be equal.



          On the other hand, the calculation that you've done is sensible if you understand what you're doing. What you actually want to see, in order to verify your original statement is that
          $$
          (Hotimes H)cdot(|00rangle-|11rangle)/sqrt2=(Hotimes H)cdot(|+-rangle+|-+rangle)/sqrt2.
          $$

          You've already calculated the left-hand side. The calculation on the right-hand side is, I suspect, the whole reason why you've chosen to apply the Hadamard transform - you know that the Hadamard converts $|+rangle$ to $|0rangle$, and $|-rangle$ to $|1rangle$. So, you can immediately read that
          $$
          (Hotimes H)cdot(|+-rangle+|-+rangle)/sqrt2=(|01rangle+|10rangle)/sqrt2,
          $$

          so you can see that the left-hand side is equal to the right-hand side, as desired.






          share|improve this answer




















          • Ok, so if I understand that correctly, I would just have to apply the Hadamard transformation on the right as well, and I would have achieved what I wanted to show?
            – P_Gate
            26 mins ago










          • @P_Gate Yes, that's correct. It's like starting with a statement 1=1. If you multiply just one side by 5, the statement becomes untrue; you have to do it to both sides.
            – DaftWullie
            18 mins ago










          • Thanks for the clarification. I was just too stupid. It is an equation, i. I also have to do what I do on the left side on the right side. Stupid to forget something like that. :) Sorry that I can not upvote your answer :( (not enough rep)
            – P_Gate
            16 mins ago















          up vote
          2
          down vote













          You've started wanting to talk about
          $$
          (|00rangle-|11rangle)/sqrt2,
          $$

          but you've then gone ahead and calculated
          $$
          (Hotimes H)cdot(|00rangle-|11rangle)/sqrt2.
          $$

          You should not expect these to be equal.



          On the other hand, the calculation that you've done is sensible if you understand what you're doing. What you actually want to see, in order to verify your original statement is that
          $$
          (Hotimes H)cdot(|00rangle-|11rangle)/sqrt2=(Hotimes H)cdot(|+-rangle+|-+rangle)/sqrt2.
          $$

          You've already calculated the left-hand side. The calculation on the right-hand side is, I suspect, the whole reason why you've chosen to apply the Hadamard transform - you know that the Hadamard converts $|+rangle$ to $|0rangle$, and $|-rangle$ to $|1rangle$. So, you can immediately read that
          $$
          (Hotimes H)cdot(|+-rangle+|-+rangle)/sqrt2=(|01rangle+|10rangle)/sqrt2,
          $$

          so you can see that the left-hand side is equal to the right-hand side, as desired.






          share|improve this answer




















          • Ok, so if I understand that correctly, I would just have to apply the Hadamard transformation on the right as well, and I would have achieved what I wanted to show?
            – P_Gate
            26 mins ago










          • @P_Gate Yes, that's correct. It's like starting with a statement 1=1. If you multiply just one side by 5, the statement becomes untrue; you have to do it to both sides.
            – DaftWullie
            18 mins ago










          • Thanks for the clarification. I was just too stupid. It is an equation, i. I also have to do what I do on the left side on the right side. Stupid to forget something like that. :) Sorry that I can not upvote your answer :( (not enough rep)
            – P_Gate
            16 mins ago













          up vote
          2
          down vote










          up vote
          2
          down vote









          You've started wanting to talk about
          $$
          (|00rangle-|11rangle)/sqrt2,
          $$

          but you've then gone ahead and calculated
          $$
          (Hotimes H)cdot(|00rangle-|11rangle)/sqrt2.
          $$

          You should not expect these to be equal.



          On the other hand, the calculation that you've done is sensible if you understand what you're doing. What you actually want to see, in order to verify your original statement is that
          $$
          (Hotimes H)cdot(|00rangle-|11rangle)/sqrt2=(Hotimes H)cdot(|+-rangle+|-+rangle)/sqrt2.
          $$

          You've already calculated the left-hand side. The calculation on the right-hand side is, I suspect, the whole reason why you've chosen to apply the Hadamard transform - you know that the Hadamard converts $|+rangle$ to $|0rangle$, and $|-rangle$ to $|1rangle$. So, you can immediately read that
          $$
          (Hotimes H)cdot(|+-rangle+|-+rangle)/sqrt2=(|01rangle+|10rangle)/sqrt2,
          $$

          so you can see that the left-hand side is equal to the right-hand side, as desired.






          share|improve this answer












          You've started wanting to talk about
          $$
          (|00rangle-|11rangle)/sqrt2,
          $$

          but you've then gone ahead and calculated
          $$
          (Hotimes H)cdot(|00rangle-|11rangle)/sqrt2.
          $$

          You should not expect these to be equal.



          On the other hand, the calculation that you've done is sensible if you understand what you're doing. What you actually want to see, in order to verify your original statement is that
          $$
          (Hotimes H)cdot(|00rangle-|11rangle)/sqrt2=(Hotimes H)cdot(|+-rangle+|-+rangle)/sqrt2.
          $$

          You've already calculated the left-hand side. The calculation on the right-hand side is, I suspect, the whole reason why you've chosen to apply the Hadamard transform - you know that the Hadamard converts $|+rangle$ to $|0rangle$, and $|-rangle$ to $|1rangle$. So, you can immediately read that
          $$
          (Hotimes H)cdot(|+-rangle+|-+rangle)/sqrt2=(|01rangle+|10rangle)/sqrt2,
          $$

          so you can see that the left-hand side is equal to the right-hand side, as desired.







          share|improve this answer












          share|improve this answer



          share|improve this answer










          answered 31 mins ago









          DaftWullie

          9,5871332




          9,5871332











          • Ok, so if I understand that correctly, I would just have to apply the Hadamard transformation on the right as well, and I would have achieved what I wanted to show?
            – P_Gate
            26 mins ago










          • @P_Gate Yes, that's correct. It's like starting with a statement 1=1. If you multiply just one side by 5, the statement becomes untrue; you have to do it to both sides.
            – DaftWullie
            18 mins ago










          • Thanks for the clarification. I was just too stupid. It is an equation, i. I also have to do what I do on the left side on the right side. Stupid to forget something like that. :) Sorry that I can not upvote your answer :( (not enough rep)
            – P_Gate
            16 mins ago

















          • Ok, so if I understand that correctly, I would just have to apply the Hadamard transformation on the right as well, and I would have achieved what I wanted to show?
            – P_Gate
            26 mins ago










          • @P_Gate Yes, that's correct. It's like starting with a statement 1=1. If you multiply just one side by 5, the statement becomes untrue; you have to do it to both sides.
            – DaftWullie
            18 mins ago










          • Thanks for the clarification. I was just too stupid. It is an equation, i. I also have to do what I do on the left side on the right side. Stupid to forget something like that. :) Sorry that I can not upvote your answer :( (not enough rep)
            – P_Gate
            16 mins ago
















          Ok, so if I understand that correctly, I would just have to apply the Hadamard transformation on the right as well, and I would have achieved what I wanted to show?
          – P_Gate
          26 mins ago




          Ok, so if I understand that correctly, I would just have to apply the Hadamard transformation on the right as well, and I would have achieved what I wanted to show?
          – P_Gate
          26 mins ago












          @P_Gate Yes, that's correct. It's like starting with a statement 1=1. If you multiply just one side by 5, the statement becomes untrue; you have to do it to both sides.
          – DaftWullie
          18 mins ago




          @P_Gate Yes, that's correct. It's like starting with a statement 1=1. If you multiply just one side by 5, the statement becomes untrue; you have to do it to both sides.
          – DaftWullie
          18 mins ago












          Thanks for the clarification. I was just too stupid. It is an equation, i. I also have to do what I do on the left side on the right side. Stupid to forget something like that. :) Sorry that I can not upvote your answer :( (not enough rep)
          – P_Gate
          16 mins ago





          Thanks for the clarification. I was just too stupid. It is an equation, i. I also have to do what I do on the left side on the right side. Stupid to forget something like that. :) Sorry that I can not upvote your answer :( (not enough rep)
          – P_Gate
          16 mins ago













          up vote
          1
          down vote













          You are not proving the equality in a correct way. By multiplying by the Hadamard matrix, you are changing the state you are trying to calculate, not demonstrating the equality you want to prove.$defket#1lvert#1rangle$



          In order to prove what you state at the beginning of the question, I would use the facts that $$
          ket+ =frac1sqrt2bigl(ket0 + ket1bigr), qquadket-=frac1sqrt2bigl(ket0 - ket1bigr),$$

          and then develop the equality in the inverse order. Consequently:
          $$
          beginalignat2
          frac1sqrt2&bigl(ket+_x ket-_y - ket-_x ket+_ybigr)mspace-128mu
          \[1ex]=;&
          frac1sqrt2Bigl(frac12bigl(&&ket0_x+ket1_xbigr)bigl(ket0_y-ket1_ybigr)+bigl(ket0_x-ket1_xbigr)bigl(ket0_y+ket1_ybigr)Bigr)
          \[1ex]=;&
          frac1sqrt2Bigl(frac12bigl(&&ket0_xket0_y+ket1_xket-_y-ket0_xket1_y-ket1_xket1_y
          \[-1ex]&&&+ket0_xket0_y+ket0_xket1_y-ket1_xket0_y-ket1_xket1_ybigr)Bigr)
          \=;&
          frac1sqrt2bigl(ket0_xket0_y - ket1_xket1_ybigr).mspace-128mu
          endalignat
          $$



          And so you prove the equality you were trying to solve at the beginning of the question.






          share|improve this answer


















          • 1




            Thanks, your answer is also helpful for me! I would upvote but I have not enough reputation :(
            – P_Gate
            15 mins ago














          up vote
          1
          down vote













          You are not proving the equality in a correct way. By multiplying by the Hadamard matrix, you are changing the state you are trying to calculate, not demonstrating the equality you want to prove.$defket#1lvert#1rangle$



          In order to prove what you state at the beginning of the question, I would use the facts that $$
          ket+ =frac1sqrt2bigl(ket0 + ket1bigr), qquadket-=frac1sqrt2bigl(ket0 - ket1bigr),$$

          and then develop the equality in the inverse order. Consequently:
          $$
          beginalignat2
          frac1sqrt2&bigl(ket+_x ket-_y - ket-_x ket+_ybigr)mspace-128mu
          \[1ex]=;&
          frac1sqrt2Bigl(frac12bigl(&&ket0_x+ket1_xbigr)bigl(ket0_y-ket1_ybigr)+bigl(ket0_x-ket1_xbigr)bigl(ket0_y+ket1_ybigr)Bigr)
          \[1ex]=;&
          frac1sqrt2Bigl(frac12bigl(&&ket0_xket0_y+ket1_xket-_y-ket0_xket1_y-ket1_xket1_y
          \[-1ex]&&&+ket0_xket0_y+ket0_xket1_y-ket1_xket0_y-ket1_xket1_ybigr)Bigr)
          \=;&
          frac1sqrt2bigl(ket0_xket0_y - ket1_xket1_ybigr).mspace-128mu
          endalignat
          $$



          And so you prove the equality you were trying to solve at the beginning of the question.






          share|improve this answer


















          • 1




            Thanks, your answer is also helpful for me! I would upvote but I have not enough reputation :(
            – P_Gate
            15 mins ago












          up vote
          1
          down vote










          up vote
          1
          down vote









          You are not proving the equality in a correct way. By multiplying by the Hadamard matrix, you are changing the state you are trying to calculate, not demonstrating the equality you want to prove.$defket#1lvert#1rangle$



          In order to prove what you state at the beginning of the question, I would use the facts that $$
          ket+ =frac1sqrt2bigl(ket0 + ket1bigr), qquadket-=frac1sqrt2bigl(ket0 - ket1bigr),$$

          and then develop the equality in the inverse order. Consequently:
          $$
          beginalignat2
          frac1sqrt2&bigl(ket+_x ket-_y - ket-_x ket+_ybigr)mspace-128mu
          \[1ex]=;&
          frac1sqrt2Bigl(frac12bigl(&&ket0_x+ket1_xbigr)bigl(ket0_y-ket1_ybigr)+bigl(ket0_x-ket1_xbigr)bigl(ket0_y+ket1_ybigr)Bigr)
          \[1ex]=;&
          frac1sqrt2Bigl(frac12bigl(&&ket0_xket0_y+ket1_xket-_y-ket0_xket1_y-ket1_xket1_y
          \[-1ex]&&&+ket0_xket0_y+ket0_xket1_y-ket1_xket0_y-ket1_xket1_ybigr)Bigr)
          \=;&
          frac1sqrt2bigl(ket0_xket0_y - ket1_xket1_ybigr).mspace-128mu
          endalignat
          $$



          And so you prove the equality you were trying to solve at the beginning of the question.






          share|improve this answer














          You are not proving the equality in a correct way. By multiplying by the Hadamard matrix, you are changing the state you are trying to calculate, not demonstrating the equality you want to prove.$defket#1lvert#1rangle$



          In order to prove what you state at the beginning of the question, I would use the facts that $$
          ket+ =frac1sqrt2bigl(ket0 + ket1bigr), qquadket-=frac1sqrt2bigl(ket0 - ket1bigr),$$

          and then develop the equality in the inverse order. Consequently:
          $$
          beginalignat2
          frac1sqrt2&bigl(ket+_x ket-_y - ket-_x ket+_ybigr)mspace-128mu
          \[1ex]=;&
          frac1sqrt2Bigl(frac12bigl(&&ket0_x+ket1_xbigr)bigl(ket0_y-ket1_ybigr)+bigl(ket0_x-ket1_xbigr)bigl(ket0_y+ket1_ybigr)Bigr)
          \[1ex]=;&
          frac1sqrt2Bigl(frac12bigl(&&ket0_xket0_y+ket1_xket-_y-ket0_xket1_y-ket1_xket1_y
          \[-1ex]&&&+ket0_xket0_y+ket0_xket1_y-ket1_xket0_y-ket1_xket1_ybigr)Bigr)
          \=;&
          frac1sqrt2bigl(ket0_xket0_y - ket1_xket1_ybigr).mspace-128mu
          endalignat
          $$



          And so you prove the equality you were trying to solve at the beginning of the question.







          share|improve this answer














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          edited 6 mins ago









          Niel de Beaudrap

          5,027830




          5,027830










          answered 19 mins ago









          Josu Etxezarreta Martinez

          926116




          926116







          • 1




            Thanks, your answer is also helpful for me! I would upvote but I have not enough reputation :(
            – P_Gate
            15 mins ago












          • 1




            Thanks, your answer is also helpful for me! I would upvote but I have not enough reputation :(
            – P_Gate
            15 mins ago







          1




          1




          Thanks, your answer is also helpful for me! I would upvote but I have not enough reputation :(
          – P_Gate
          15 mins ago




          Thanks, your answer is also helpful for me! I would upvote but I have not enough reputation :(
          – P_Gate
          15 mins ago










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