Understanding this description of teleportationQuantum algorithm for linear systems of equations (HHL09): Step 1 - Confusion regarding the usage of phase estimation algorithmQuantum algorithm for linear systems of equations (HHL09): Step 2 - What is $|Psi_0rangle$?HHL algorithm — problem with the outcome of postselectionQutrit TeleportationGeneral construction of $W_n$-stateCalculating measurement result of quantum swap circuitQuantum teleportation: second classical bit for removing entanglement?Weeding out qubit states with leftmost qubit as 1Clarification of the “Calculations” section of the (HHL09) paperQuantum secret Sharing using GHZ state paper

Are 变 and 変 the same?

Is there any way to stop a user from creating executables and running them?

What are these funnel-looking green things in my yard?

Safest way to store environment variable value in a file

How exactly are corporate bonds priced at issue

Is there a Morita cocycle for the mapping class group Mod(g,n) when n > 1?

How to disable "Completion time:..." in SQL Server Messages window

how do companies get money from being listed publicly

Simplification of numbers

Is There a Tool to Select Files to Download From an Org in VSCode?

If clocks themselves are based on light signals, wouldn't we expect the measured speed of light to always be the same constant?

Why did I get only 5 points even though I won?

Boss wants me to ignore a software API license prohibiting mass download

On the Rømer experiments and the speed of light

What should I call bands of armed men in the Middle Ages?

What is this "Table of astronomy" about?

The cat ate your input again!

Collinear Galois conjugates

How can God warn people of the upcoming rapture without disrupting society?

A continuous water "planet" ring around a star

How many people would you need to pull a whale over cobblestone streets?

Does fossil fuels use since 1990 account for half of all the fossil fuels used in history?

Are employers legally allowed to pay employees in goods and services equal to or greater than the minimum wage?

How far did Gandalf and the Balrog drop from the bridge in Moria?



Understanding this description of teleportation


Quantum algorithm for linear systems of equations (HHL09): Step 1 - Confusion regarding the usage of phase estimation algorithmQuantum algorithm for linear systems of equations (HHL09): Step 2 - What is $|Psi_0rangle$?HHL algorithm — problem with the outcome of postselectionQutrit TeleportationGeneral construction of $W_n$-stateCalculating measurement result of quantum swap circuitQuantum teleportation: second classical bit for removing entanglement?Weeding out qubit states with leftmost qubit as 1Clarification of the “Calculations” section of the (HHL09) paperQuantum secret Sharing using GHZ state paper






.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;








5












$begingroup$


In the context of quantum teleportation, my lecturer writes the following (note that I assume the reader is familiar with the circuit):



If the measurement of the first qubit is 0 and the measurement of the second qubit is 0 , then we have the state $left|phi_4right>=c_0left|000right>+c_1left|001right>=left|00right>otimes left(c_0left|0right>+c_1left|1right>right)=left|00right> otimes left|psi 'right>$.



Now to get the final teleported state we have to go through the final two gates $Z, X$.



My lecturer writes this as;



$left|gammaright>=Z^0X^0left|psi 'right>= left|psi'right>= c_0left|0right>+c_1left|1right>$



Here are my questions:



  1. Why is it that the we do not have $left|gammaright>=Z^0X^0left(left|00right>otimes left|psi 'right>right)$? I don't understand why we cut the state $left|phi_4right>$ "in half ", to use bad terminology, at this step.


  2. What does the superscript 0 on the operators refer to?


  3. In the final state again to use bad terminology we only use half of the state $left|phi_4right>$ can we always assume that the final state will be the $left|psi'right>$ part of $left|phi_4right>=left|xyright>otimesleft|psi'right>$ state, and if so what is the significance of the final step.


If my question is unanswerable due to a deep misunderstanding of the math processes here, I'd still really appreciate some clarification on whatever points can be answered and I can edit it to make more sense as I learn.










share|improve this question











$endgroup$




















    5












    $begingroup$


    In the context of quantum teleportation, my lecturer writes the following (note that I assume the reader is familiar with the circuit):



    If the measurement of the first qubit is 0 and the measurement of the second qubit is 0 , then we have the state $left|phi_4right>=c_0left|000right>+c_1left|001right>=left|00right>otimes left(c_0left|0right>+c_1left|1right>right)=left|00right> otimes left|psi 'right>$.



    Now to get the final teleported state we have to go through the final two gates $Z, X$.



    My lecturer writes this as;



    $left|gammaright>=Z^0X^0left|psi 'right>= left|psi'right>= c_0left|0right>+c_1left|1right>$



    Here are my questions:



    1. Why is it that the we do not have $left|gammaright>=Z^0X^0left(left|00right>otimes left|psi 'right>right)$? I don't understand why we cut the state $left|phi_4right>$ "in half ", to use bad terminology, at this step.


    2. What does the superscript 0 on the operators refer to?


    3. In the final state again to use bad terminology we only use half of the state $left|phi_4right>$ can we always assume that the final state will be the $left|psi'right>$ part of $left|phi_4right>=left|xyright>otimesleft|psi'right>$ state, and if so what is the significance of the final step.


    If my question is unanswerable due to a deep misunderstanding of the math processes here, I'd still really appreciate some clarification on whatever points can be answered and I can edit it to make more sense as I learn.










    share|improve this question











    $endgroup$
















      5












      5








      5





      $begingroup$


      In the context of quantum teleportation, my lecturer writes the following (note that I assume the reader is familiar with the circuit):



      If the measurement of the first qubit is 0 and the measurement of the second qubit is 0 , then we have the state $left|phi_4right>=c_0left|000right>+c_1left|001right>=left|00right>otimes left(c_0left|0right>+c_1left|1right>right)=left|00right> otimes left|psi 'right>$.



      Now to get the final teleported state we have to go through the final two gates $Z, X$.



      My lecturer writes this as;



      $left|gammaright>=Z^0X^0left|psi 'right>= left|psi'right>= c_0left|0right>+c_1left|1right>$



      Here are my questions:



      1. Why is it that the we do not have $left|gammaright>=Z^0X^0left(left|00right>otimes left|psi 'right>right)$? I don't understand why we cut the state $left|phi_4right>$ "in half ", to use bad terminology, at this step.


      2. What does the superscript 0 on the operators refer to?


      3. In the final state again to use bad terminology we only use half of the state $left|phi_4right>$ can we always assume that the final state will be the $left|psi'right>$ part of $left|phi_4right>=left|xyright>otimesleft|psi'right>$ state, and if so what is the significance of the final step.


      If my question is unanswerable due to a deep misunderstanding of the math processes here, I'd still really appreciate some clarification on whatever points can be answered and I can edit it to make more sense as I learn.










      share|improve this question











      $endgroup$




      In the context of quantum teleportation, my lecturer writes the following (note that I assume the reader is familiar with the circuit):



      If the measurement of the first qubit is 0 and the measurement of the second qubit is 0 , then we have the state $left|phi_4right>=c_0left|000right>+c_1left|001right>=left|00right>otimes left(c_0left|0right>+c_1left|1right>right)=left|00right> otimes left|psi 'right>$.



      Now to get the final teleported state we have to go through the final two gates $Z, X$.



      My lecturer writes this as;



      $left|gammaright>=Z^0X^0left|psi 'right>= left|psi'right>= c_0left|0right>+c_1left|1right>$



      Here are my questions:



      1. Why is it that the we do not have $left|gammaright>=Z^0X^0left(left|00right>otimes left|psi 'right>right)$? I don't understand why we cut the state $left|phi_4right>$ "in half ", to use bad terminology, at this step.


      2. What does the superscript 0 on the operators refer to?


      3. In the final state again to use bad terminology we only use half of the state $left|phi_4right>$ can we always assume that the final state will be the $left|psi'right>$ part of $left|phi_4right>=left|xyright>otimesleft|psi'right>$ state, and if so what is the significance of the final step.


      If my question is unanswerable due to a deep misunderstanding of the math processes here, I'd still really appreciate some clarification on whatever points can be answered and I can edit it to make more sense as I learn.







      algorithm quantum-state quantum-information teleportation






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited Apr 15 at 5:24









      Sanchayan Dutta

      8,0774 gold badges18 silver badges63 bronze badges




      8,0774 gold badges18 silver badges63 bronze badges










      asked Apr 14 at 23:22









      bhapibhapi

      3798 bronze badges




      3798 bronze badges























          1 Answer
          1






          active

          oldest

          votes


















          5












          $begingroup$

          1. The first two qubits stay on the sender's side, and since they are not entangled with the receiver's qubit, it's not necessary to mention them any further — we switched to discussing the receiver's side of the protocol, and all information from the first two qubits is now in measurement results.


          2. The superscripts denote the power of the operator applied: if both measurement results are 0, you don't need to apply X or Z corrections, which is the same as applying these operators raised to power 0 ($X^0 = Z^0 = I$).


          3. After measuring the first two qubits, the state will always be represented as $|xyrangle otimes |textsome staterangle$, but to convert the receiver's qubit from $|textsome staterangle$ to the state that needed to be teleported $|psi'rangle$ you'll need to apply corrections which depend on the measurement results $x$ and $y$. I believe this is what you refer to as the final step, and its goal is fixing the amplitudes of the state for it to match the state that was teleported.






          share|improve this answer











          $endgroup$










          • 1




            $begingroup$
            Minor nitpicks. If you write text within a mathematical expression it's best to use the text formatting; otherwise, the $spacing space between space letters space is space somewhat space uneven$. Moreover, 1., 2. and 3. is the only format that works for numbered lists (on SE). 1), 2) and 3) does not work. Cf. help/formatting. I've edited these things; hope you don't mind. Also, it might be useful to clarify the Alice-Bob terminology in the answer itself as the OP doesn't seem to be using it.
            $endgroup$
            – Sanchayan Dutta
            Apr 15 at 5:31














          Your Answer








          StackExchange.ready(function()
          var channelOptions =
          tags: "".split(" "),
          id: "694"
          ;
          initTagRenderer("".split(" "), "".split(" "), channelOptions);

          StackExchange.using("externalEditor", function()
          // Have to fire editor after snippets, if snippets enabled
          if (StackExchange.settings.snippets.snippetsEnabled)
          StackExchange.using("snippets", function()
          createEditor();
          );

          else
          createEditor();

          );

          function createEditor()
          StackExchange.prepareEditor(
          heartbeatType: 'answer',
          autoActivateHeartbeat: false,
          convertImagesToLinks: false,
          noModals: true,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: null,
          bindNavPrevention: true,
          postfix: "",
          imageUploader:
          brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
          contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
          allowUrls: true
          ,
          noCode: true, onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          );



          );













          draft saved

          draft discarded


















          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fquantumcomputing.stackexchange.com%2fquestions%2f5913%2funderstanding-this-description-of-teleportation%23new-answer', 'question_page');

          );

          Post as a guest















          Required, but never shown

























          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          5












          $begingroup$

          1. The first two qubits stay on the sender's side, and since they are not entangled with the receiver's qubit, it's not necessary to mention them any further — we switched to discussing the receiver's side of the protocol, and all information from the first two qubits is now in measurement results.


          2. The superscripts denote the power of the operator applied: if both measurement results are 0, you don't need to apply X or Z corrections, which is the same as applying these operators raised to power 0 ($X^0 = Z^0 = I$).


          3. After measuring the first two qubits, the state will always be represented as $|xyrangle otimes |textsome staterangle$, but to convert the receiver's qubit from $|textsome staterangle$ to the state that needed to be teleported $|psi'rangle$ you'll need to apply corrections which depend on the measurement results $x$ and $y$. I believe this is what you refer to as the final step, and its goal is fixing the amplitudes of the state for it to match the state that was teleported.






          share|improve this answer











          $endgroup$










          • 1




            $begingroup$
            Minor nitpicks. If you write text within a mathematical expression it's best to use the text formatting; otherwise, the $spacing space between space letters space is space somewhat space uneven$. Moreover, 1., 2. and 3. is the only format that works for numbered lists (on SE). 1), 2) and 3) does not work. Cf. help/formatting. I've edited these things; hope you don't mind. Also, it might be useful to clarify the Alice-Bob terminology in the answer itself as the OP doesn't seem to be using it.
            $endgroup$
            – Sanchayan Dutta
            Apr 15 at 5:31
















          5












          $begingroup$

          1. The first two qubits stay on the sender's side, and since they are not entangled with the receiver's qubit, it's not necessary to mention them any further — we switched to discussing the receiver's side of the protocol, and all information from the first two qubits is now in measurement results.


          2. The superscripts denote the power of the operator applied: if both measurement results are 0, you don't need to apply X or Z corrections, which is the same as applying these operators raised to power 0 ($X^0 = Z^0 = I$).


          3. After measuring the first two qubits, the state will always be represented as $|xyrangle otimes |textsome staterangle$, but to convert the receiver's qubit from $|textsome staterangle$ to the state that needed to be teleported $|psi'rangle$ you'll need to apply corrections which depend on the measurement results $x$ and $y$. I believe this is what you refer to as the final step, and its goal is fixing the amplitudes of the state for it to match the state that was teleported.






          share|improve this answer











          $endgroup$










          • 1




            $begingroup$
            Minor nitpicks. If you write text within a mathematical expression it's best to use the text formatting; otherwise, the $spacing space between space letters space is space somewhat space uneven$. Moreover, 1., 2. and 3. is the only format that works for numbered lists (on SE). 1), 2) and 3) does not work. Cf. help/formatting. I've edited these things; hope you don't mind. Also, it might be useful to clarify the Alice-Bob terminology in the answer itself as the OP doesn't seem to be using it.
            $endgroup$
            – Sanchayan Dutta
            Apr 15 at 5:31














          5












          5








          5





          $begingroup$

          1. The first two qubits stay on the sender's side, and since they are not entangled with the receiver's qubit, it's not necessary to mention them any further — we switched to discussing the receiver's side of the protocol, and all information from the first two qubits is now in measurement results.


          2. The superscripts denote the power of the operator applied: if both measurement results are 0, you don't need to apply X or Z corrections, which is the same as applying these operators raised to power 0 ($X^0 = Z^0 = I$).


          3. After measuring the first two qubits, the state will always be represented as $|xyrangle otimes |textsome staterangle$, but to convert the receiver's qubit from $|textsome staterangle$ to the state that needed to be teleported $|psi'rangle$ you'll need to apply corrections which depend on the measurement results $x$ and $y$. I believe this is what you refer to as the final step, and its goal is fixing the amplitudes of the state for it to match the state that was teleported.






          share|improve this answer











          $endgroup$



          1. The first two qubits stay on the sender's side, and since they are not entangled with the receiver's qubit, it's not necessary to mention them any further — we switched to discussing the receiver's side of the protocol, and all information from the first two qubits is now in measurement results.


          2. The superscripts denote the power of the operator applied: if both measurement results are 0, you don't need to apply X or Z corrections, which is the same as applying these operators raised to power 0 ($X^0 = Z^0 = I$).


          3. After measuring the first two qubits, the state will always be represented as $|xyrangle otimes |textsome staterangle$, but to convert the receiver's qubit from $|textsome staterangle$ to the state that needed to be teleported $|psi'rangle$ you'll need to apply corrections which depend on the measurement results $x$ and $y$. I believe this is what you refer to as the final step, and its goal is fixing the amplitudes of the state for it to match the state that was teleported.







          share|improve this answer














          share|improve this answer



          share|improve this answer








          edited Apr 15 at 6:04

























          answered Apr 15 at 5:24









          Mariia MykhailovaMariia Mykhailova

          3,3401 gold badge3 silver badges21 bronze badges




          3,3401 gold badge3 silver badges21 bronze badges










          • 1




            $begingroup$
            Minor nitpicks. If you write text within a mathematical expression it's best to use the text formatting; otherwise, the $spacing space between space letters space is space somewhat space uneven$. Moreover, 1., 2. and 3. is the only format that works for numbered lists (on SE). 1), 2) and 3) does not work. Cf. help/formatting. I've edited these things; hope you don't mind. Also, it might be useful to clarify the Alice-Bob terminology in the answer itself as the OP doesn't seem to be using it.
            $endgroup$
            – Sanchayan Dutta
            Apr 15 at 5:31













          • 1




            $begingroup$
            Minor nitpicks. If you write text within a mathematical expression it's best to use the text formatting; otherwise, the $spacing space between space letters space is space somewhat space uneven$. Moreover, 1., 2. and 3. is the only format that works for numbered lists (on SE). 1), 2) and 3) does not work. Cf. help/formatting. I've edited these things; hope you don't mind. Also, it might be useful to clarify the Alice-Bob terminology in the answer itself as the OP doesn't seem to be using it.
            $endgroup$
            – Sanchayan Dutta
            Apr 15 at 5:31








          1




          1




          $begingroup$
          Minor nitpicks. If you write text within a mathematical expression it's best to use the text formatting; otherwise, the $spacing space between space letters space is space somewhat space uneven$. Moreover, 1., 2. and 3. is the only format that works for numbered lists (on SE). 1), 2) and 3) does not work. Cf. help/formatting. I've edited these things; hope you don't mind. Also, it might be useful to clarify the Alice-Bob terminology in the answer itself as the OP doesn't seem to be using it.
          $endgroup$
          – Sanchayan Dutta
          Apr 15 at 5:31





          $begingroup$
          Minor nitpicks. If you write text within a mathematical expression it's best to use the text formatting; otherwise, the $spacing space between space letters space is space somewhat space uneven$. Moreover, 1., 2. and 3. is the only format that works for numbered lists (on SE). 1), 2) and 3) does not work. Cf. help/formatting. I've edited these things; hope you don't mind. Also, it might be useful to clarify the Alice-Bob terminology in the answer itself as the OP doesn't seem to be using it.
          $endgroup$
          – Sanchayan Dutta
          Apr 15 at 5:31


















          draft saved

          draft discarded
















































          Thanks for contributing an answer to Quantum Computing Stack Exchange!


          • Please be sure to answer the question. Provide details and share your research!

          But avoid


          • Asking for help, clarification, or responding to other answers.

          • Making statements based on opinion; back them up with references or personal experience.

          Use MathJax to format equations. MathJax reference.


          To learn more, see our tips on writing great answers.




          draft saved


          draft discarded














          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fquantumcomputing.stackexchange.com%2fquestions%2f5913%2funderstanding-this-description-of-teleportation%23new-answer', 'question_page');

          );

          Post as a guest















          Required, but never shown





















































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown

































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown







          Popular posts from this blog

          Tamil (spriik) Luke uk diar | Nawigatjuun

          Align equal signs while including text over equalitiesAMS align: left aligned text/math plus multicolumn alignmentMultiple alignmentsAligning equations in multiple placesNumbering and aligning an equation with multiple columnsHow to align one equation with another multline equationUsing \ in environments inside the begintabularxNumber equations and preserving alignment of equal signsHow can I align equations to the left and to the right?Double equation alignment problem within align enviromentAligned within align: Why are they right-aligned?

          Where does the image of a data connector as a sharp metal spike originate from?Where does the concept of infected people turning into zombies only after death originate from?Where does the motif of a reanimated human head originate?Where did the notion that Dragons could speak originate?Where does the archetypal image of the 'Grey' alien come from?Where did the suffix '-Man' originate?Where does the notion of being injured or killed by an illusion originate?Where did the term “sophont” originate?Where does the trope of magic spells being driven by advanced technology originate from?Where did the term “the living impaired” originate?