Read the description of the phenomenon and complete the sentences with the correct terms.

                                                                                                                                               

BCS theory  The Josephson effect Cooper pair  The Meissner effect Josephson junction/current

 

1 _____ ____, the expulsion (вытеснение) of a magnetic field from the interior of a material that is in the process of becoming a superconductor, that is losing its resistance to the flow of electrical currents when cooled below a certain temperature, usually close to absolute zero.

2 The central feature of the ______ ____is that two electrons in the superconductor are able to form a bound called a _____ ________ if they somehow experience an attractive interaction.

3 ______ _____, flow of electric current between two pieces of superconducting material separated by a thin layer of insulating material. This arrangement – two superconductors linked by a non-conducting barrier- is known as a _____ ______, the current that crosses the barrier is the____ _____

 

Complete the sentences with the correct names of the scientists.

 1 The Meissner effect, a property of all superconductors, was discovered by the German physicists ____________ and___________

 2 The BCS theory, the first microscopic theory of superconductivity since the discovery in1911 is named after ________, __________, and ____________.

 3_________had discovered that electrons in a superconductor are grouped in pairs, now called Cooper pairs, and that the motions of all of the Cooper pairs within a single superconductor are correlated; they constitute a system that functions as a single entity.

 

8. Translate these sentences into English.

1 Эффект Джозефсона это явление протекания сверхпроводящего тока через тонкий слой диэлектрика, разделяющий два сверхпроводника. Такой ток называют током Джозефсона,

а такое соединение сверхпроводников - контактом Джозефсона.

2 Эффект Мейснера заключается в том, что постоянное не слишком сильное магнитное поле выталкивается из сверхпроводящего магнитного образца. В толще сверхпроводника   магнитное поле ослабляется до нуля. 

3  Как представлял себе Купер, между двумя электронами существует притяжение, которое

 должно приводить к образованию связанных пар. Такие пары стали называть куперовскими

 

Look, no magnetism!

 

9. Watch the video Meissner effect and answer the questions. Then describe the experiment.

Useful notes:

Yttrium barium copper oxide (YBCO) – широко применяемый высокотемпературный

сверхпроводник оксид иттрия-бария-меди. Он является первым полученным

сверхпроводником с критической температурой больше 77К (Тк=92К)

moisture - влага

fragile - хрупкий

levitate - парить в воздухе

 

1 What was used as a superconducting sample in the experiment?

2 Why shouldn’t you touch the superconductor with your hands?

3 What was put on top of the superconductor?

4 What was liquid nitrogen used for?

5 What happened with the magnet?   

 

Study the rules

I WISH I KNEW…

Rules:

When the situation is not real and you imagine it, we use if + past (if I knew / if you were / if we didn’t etc.) We use the past in the same way after wish (I wish I knew / I wish you were etc.

We use wish + past simple to express our wishes for the present, to say that we regret something, that something is not as we would like it to be:

 

I wish I didn’t live in a big city. (The real situation is that I live in a big city and I don’t like it).

I wish Ann were / was here. (The real situation is that Ann is not here and I need to see her).

 

After if and wish, you can use were instead of was (If I were, I wish it were etc.)

 

I wish it were possible (or I wish it was possible.)

11. Write sentences beginning I wish

 

Example: I don’t know Paul’s phone number and I regret this.

            I wish I knew Paul’s phone number.

1. You don’t have a key but you need it.

You say: I wish …

2. You want to buy a book but it’s too expensive.

You say; I wish …

3. You want to conduct an experiment in superconductivity but there are no superconducting samples in your laboratory.

You say: I wish…

4. You don’t know anything about cars but you car has just broken down.

You say; I wish …

5. You don’t know his address. You would like to know but you can’t find it out now.

You say: I wish …

6. Mary has to work on Saturday. She is sorry that she has to work on Saturday.

Mary wishes …

12. Write your own sentences beginning I wish…

 

Example: I wish I had a highly paid job.

 

1. (something you’d like to have – a high-speed computer, a prestigious car, etc.)

I wish I…

2. (something you’d like to be able to do – play a musical instrument, speak a foreign language etc.)

I wish I…

3. (somewhere you’d like to be now – in Saint Petersburg, at a football match, in a café etc.)

I wish I…