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Борис В. Васильев Сверхтекучесть и Сверхпроводимость

Борис В. Васильев
Сверхтекучесть и Сверхпроводимость

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Ýòî ðåøåíèå âåñüìà òî÷íî ñîâïàäàåò ñ ðåøåíèåì<br />

ñîîòâåòñòâóþùåãî èíòåãðàëüíîãî óðàâíåíèÿ<br />

ÁÊØ, ïîñòðîåííîãî íà ó÷åòå ôîíîííîãî<br />

ñïåêòðà (ñì.ðèñ(3.5)), è âïîëíå óäîâëåòâîðèòåëüíî<br />

ñîãëàñóåòñÿ äàííûìè èçìåðåíèé.<br />

×èñëåííî èíòåãðèðóÿ ïîëó÷åííóþ çàâèñèìîñòü<br />

âåëè÷èíû ùåëè ïî òåìïåðàòóðå, ïîëó÷àåì<br />

óñðåäíåííóþ âåëè÷èíó ùåëè:<br />

(74) 〈∆〉 = ∆ 0<br />

∫ 1<br />

0<br />

δdt = 0.852 ∆ 0 .<br />

×òîáû ïåðåâåñòè êîíäåíñàò íóëåâûõ êîëåáàíèé<br />

â íîðìàëüíîå ñîñòîÿíèå íóæíî ïåðåâåñòè<br />

â âîçáóæäåííîå ñîñòîÿíèå ïîëîâèíó åãî ÷àñòèö<br />

(ñîãëàñíî (72) ïðè ýòîì óñëîâèè ùåëü ñõëîïíåòñÿ).<br />

Äëÿ ýòîãî ñ ó÷åòîì (74) êîíäåíñàòó â åäèíèöå<br />

îáúåìà íóæíî ñîîáùèòü ýíåðãèþ:<br />

(75) E T ≃ 1 2 n 0〈∆ 0 〉 ≃ 0.85<br />

2<br />

( me<br />

0 ,<br />

2π 2 α 2 ) 3/2<br />

∆<br />

5/2<br />

Ñ äðóãîé ñòîðîíû, ïîëó÷èòü íîðìàëüíîå ñîñòîÿíèå<br />

ìîæíî, ïðèëîæèâ ìàãíèòíîå ïîëå ñ<br />

ïëîòíîñòüþ ýíåðãèè:<br />

(76) E H = H2 c<br />

8π .<br />

Ïðèðàâíÿâ ýòè äâå ýíåðãèè (îòíåñåííûå ê åäèíèöå<br />

îáúåìà)<br />

(77)<br />

1<br />

2 n 0〈∆ 0 〉 = H2 c<br />

8π ,<br />

107

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