I need clarification about Bell state Measurements

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Discussion Overview

The discussion revolves around the clarification of Bell state measurements, particularly in the context of superdense coding. Participants explore the implications of measuring the first qubit in various Bell states and the resulting states of the second qubit.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification

Main Points Raised

  • One participant lists the four Bell states and describes their initial understanding of superdense coding, specifically how measuring the first qubit affects the second qubit's state.
  • The participant expresses confusion regarding the outcomes of measurements on the second qubit based on the first qubit's measurement, particularly contrasting the first and second Bell states.
  • Another participant suggests resources for further study, indicating a familiarity with quantum information theory and recommending lecture notes from John Preskill.
  • One participant mentions their project on quantum computing, indicating a personal interest in the topic.

Areas of Agreement / Disagreement

The discussion reflects a lack of consensus on the implications of measuring the first qubit in Bell states, with one participant expressing confusion and seeking clarification. Other participants provide resources but do not directly address the specific confusion raised.

Contextual Notes

The discussion does not resolve the assumptions or conditions under which the measurements are made, nor does it clarify the implications of the Bell states in superdense coding.

Who May Find This Useful

Individuals interested in quantum information theory, quantum computing, or those seeking clarification on Bell states and their measurements may find this discussion relevant.

Baggio
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The four bell states are

1: (|00>+|11>)(2)^-0.5
2: (|00>-|11>)(2)^-0.5
3: (|01>+|10>)(2)^-0.5
4: (|01>-|10>)(2)^-0.5

I'm looking at super dense coding and the way i thought of it at first was that if a measurement of the first qubit was made then if we consider the first bell state (1) if 0 is the value obtained then the system if forced into the state |00> so that measurement of the second qubit yields 0 with certainty..

Now take (2) if we measure the first qubit and we get 0 then apparently measurement of the 2nd qubit yields 1 with certainty.. So my way of thinking isn't correct lol

Can someone clarify?
 
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Seems to me you are really into QIT...

Check out this site of John Preskill. All the answers are in the links to lecture notes, they are highly recommended. I studied quantum info theory from these lectures at college...
http://www.theory.caltech.edu/~preskill/ph219/
marlon
 
I'm doing a project on Quantum computing :D
 
well, you will find everything in them notes...feel free to ask more questions though

marlon
 

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