Quantum Bomb Detector Elitzur–Vaidman

Hello Guys! Welcome to our world of Awesomeness !! Technology!! I am going to post one fascinating topic related to science and technology every week feel free to question me anything about technology. Now without any further delay Lets Roll inside!!!!

Elitzur and Vaidman are two great people who made this Thought experiment and this deals with detecting if a bomb is active or not without interacting with it which is called Interactive Free Measuring

I hope every one of us knows about Schrodinger and his thought experiment yeah!!!! you have guessed it right Schrodinger's cat experiment(Thought) which explains that the cat inside the box is both alive and dead at the same time before we open the box ...... This takes us to Superposition

Superposition: An object exists at all possible states and the act of Measuring the object forces it to Choose a definite state

Now let us take a set of Light Sensitive bombs which implies that if a photon interacts with it...Boom... it just explodes

Mach-Zehnder interferometer


Let's look at the above picture where

A is the light source
B is definitely the Bomb holder
C and D are Light Detectors
and We Have 4 Sliver Coated Beam Splitters

Now, If we turn on the light source the light ray falls on the first splitter and gets split perpendicularly and the two rays from splitter 2 and 4 interfere with each other forming constructive and destructive interference hence the light is fully recollected at the detector D

If we now slow down the light and let only a single photon of light hit the splitter 1 here the effect of Superposition is seen the photon now can travel to both the paths up and down and hence the photons are collected Fully at detector D
The probabilities are :
                                Photon gets Detected in Detector D -100%
                                Photon gets Detected in Detector C - 0%(due to interference)
                           
Now......
If we take a defective piece of a bomb and insert it in the bomb holder the (bomb doesn't explode) and the photon is collected in the detector D itself

Now let us consider an exciting case !! A Working bomb

                  Here a working Bomb is placed in the bomb holder and the experiment is repeated...

As I Said you earlier about superposition that the act of Measuring the object forces the photon to take a single state


Now let's talk about some probabilities:
                                  The photon takes the way up - 50%
                                  The photon gets detected in Detector D -25%
                                  The photon gets detected in Detector C -25%
                                   The photon takes the way down - 50%

Now if the photon takes the way down the bomb explodes and we can't detect any photon in any of the detectors

If the photons take the way up and get detected in Detector - D its uncertain that if the bomb is working or not

And If the Photon get Detected in Detector - C Then we have found that the bomb is Working and we have figured it out without interacting with it or detonating it.

Isn't this Awesome I understand that 25% Success rate is not that great but still the science behind this is Great

 Hence I thought to explain this simple yet beautiful topic to you all. Thanks for reading and I will bring some great topics like this regularly every week on Thursday

      Hope you all enjoyed it Thanks for reading and feel free to comment if you want to know about this further or anything fascinating about science and technology