25:
447:
158:, which remains superfluid at 2 Kelvin, is much more practical, but its quantum whistling is too weak to be heard with a single practical-sized hole. This problem was overcome by using barriers with thousands of holes, in effect a chorus of quantum whistles producing sound waves that reinforced one another by
134:
has come to refer generically to the different behaviors that occur in any two weakly connected macroscopic quantum systems—systems composed of molecules that all possess identical wavelike properties. Among other things, the
Josephson effect means that when two
146:. A ring-shaped tube full of superfluid, blocked by a barrier containing a tiny hole, could in principle be used to detect pressure differences caused by changes in rotational motion of the ring, in effect functioning as a sensitive
235:
139:(zero friction fluids) are connected using a weak link and pressure is applied to the superfluid on one side of a weak link, the fluid will oscillate from one side of the weak link to the other.
142:
This phenomenon, known as quantum whistling, occurs when pressure is applied to push a superfluid through a very small hole, somewhat as sound is produced by blowing air through an ordinary
285:
54:
258:
112:, Berkeley. The extreme sensitivity means that theoretically, a larger version could detect effects like minute changes in the rotational rate of the Earth.
128:
hypothesized that an electric current could travel between two superconducting materials even when they were separated by a thin insulating layer. The term
492:
526:
173:
154:, which has the disadvantage of being scarce and expensive, and requiring extremely low temperature (a few thousandths of a Kelvin). Common
350:
Barker, B. M.; O'Connell, R. F. (1970). "Derivation of the
Equations of Motion of a Gyroscope from the Quantum Theory of Gravitation".
435:
76:
297:
Simmonds, R. W.; Marchenkov, A.; Hoskinson, E.; Davis, J. C.; Packard, R. E. (2001). "Quantum interference of superfluid 3He".
485:
425:
37:
388:
47:
41:
33:
521:
511:
478:
430:
159:
58:
109:
410:
121:
415:
359:
306:
516:
338:
263:
375:
330:
322:
101:
462:
243:
367:
314:
130:
97:
454:
125:
105:
363:
310:
16:
Device used for orientation based on quantum mechanics, it is the most sensitive version
505:
342:
446:
458:
136:
379:
326:
420:
371:
230:{\displaystyle I_{c}\propto \cos \pi {\frac {2\Omega \cdot A}{\kappa _{s}}}}
147:
92:
334:
155:
151:
143:
318:
18:
466:
150:. Superfluid whistling was first demonstrated using
266:
246:
176:
389:"Superfluid helium-4 whistles just the right tune"
279:
260:is the rotation vector, A is the area vector, and
252:
229:
46:but its sources remain unclear because it lacks
486:
104:principles. The first of these was built by
8:
287:is the quantum of circulation of helium-3.
493:
479:
271:
265:
245:
219:
199:
181:
175:
77:Learn how and when to remove this message
96:is a very sensitive device to measure
7:
443:
441:
465:. You can help Knowledge (XXG) by
247:
205:
14:
436:Hemispherical resonator gyroscope
445:
23:
527:Standards and measurement stubs
387:Robert Sanders (31 Jan 2005).
1:
426:Vibrating structure gyroscope
280:{\displaystyle \kappa _{s}}
543:
440:
108:and his colleagues at the
431:Inertial measurement unit
160:constructive interference
411:Polariton interferometer
110:University of California
32:This article includes a
372:10.1103/PhysRevD.2.1428
253:{\displaystyle \Omega }
61:more precise citations.
461:-related article is a
281:
254:
231:
282:
255:
232:
416:Ring laser gyroscope
391:. Innovations Report
264:
244:
174:
122:Cambridge University
364:1970PhRvD...2.1428B
311:2001Natur.412...55S
277:
250:
227:
102:quantum mechanical
34:list of references
522:Quantum mechanics
512:Superconductivity
474:
473:
352:Physical Review D
225:
87:
86:
79:
534:
495:
488:
481:
449:
442:
400:
398:
396:
383:
358:(8): 1428–1435.
346:
319:10.1038/35083518
286:
284:
283:
278:
276:
275:
259:
257:
256:
251:
236:
234:
233:
228:
226:
224:
223:
214:
200:
186:
185:
131:Josephson effect
98:angular rotation
82:
75:
71:
68:
62:
57:this article by
48:inline citations
27:
26:
19:
542:
541:
537:
536:
535:
533:
532:
531:
502:
501:
500:
499:
407:
394:
392:
386:
349:
305:(6842): 55–58.
296:
293:
267:
262:
261:
242:
241:
215:
201:
177:
172:
171:
168:
126:Brian Josephson
118:
106:Richard Packard
83:
72:
66:
63:
52:
38:related reading
28:
24:
17:
12:
11:
5:
540:
538:
530:
529:
524:
519:
514:
504:
503:
498:
497:
490:
483:
475:
472:
471:
450:
439:
438:
433:
428:
423:
418:
413:
406:
403:
402:
401:
384:
347:
292:
289:
274:
270:
249:
238:
237:
222:
218:
213:
210:
207:
204:
198:
195:
192:
189:
184:
180:
167:
164:
117:
114:
85:
84:
42:external links
31:
29:
22:
15:
13:
10:
9:
6:
4:
3:
2:
539:
528:
525:
523:
520:
518:
515:
513:
510:
509:
507:
496:
491:
489:
484:
482:
477:
476:
470:
468:
464:
460:
456:
451:
448:
444:
437:
434:
432:
429:
427:
424:
422:
419:
417:
414:
412:
409:
408:
404:
390:
385:
381:
377:
373:
369:
365:
361:
357:
353:
348:
344:
340:
336:
332:
328:
324:
320:
316:
312:
308:
304:
300:
295:
294:
290:
288:
272:
268:
220:
216:
211:
208:
202:
196:
193:
190:
187:
182:
178:
170:
169:
165:
163:
161:
157:
153:
149:
145:
140:
138:
133:
132:
127:
123:
115:
113:
111:
107:
103:
99:
95:
94:
81:
78:
70:
60:
56:
50:
49:
43:
39:
35:
30:
21:
20:
467:expanding it
452:
393:. Retrieved
355:
351:
302:
298:
239:
141:
129:
124:PhD student
119:
90:
88:
73:
64:
53:Please help
45:
459:measurement
137:superfluids
59:introducing
517:Gyroscopes
506:Categories
291:References
455:standards
421:Gyroscope
380:0556-2821
327:0028-0836
269:κ
248:Ω
217:κ
209:⋅
206:Ω
197:π
194:
188:∝
148:gyroscope
120:In 1962,
116:Principle
100:based on
93:gyroscope
67:June 2016
405:See also
335:11452302
166:Equation
156:helium-4
152:helium-3
91:quantum
360:Bibcode
343:4413976
307:Bibcode
144:whistle
55:improve
395:30 Mar
378:
341:
333:
325:
299:Nature
240:Where
457:- or
453:This
339:S2CID
40:, or
463:stub
397:2019
376:ISSN
331:PMID
323:ISSN
368:doi
315:doi
303:412
191:cos
508::
374:.
366:.
354:.
337:.
329:.
321:.
313:.
301:.
162:.
89:A
44:,
36:,
494:e
487:t
480:v
469:.
399:.
382:.
370::
362::
356:2
345:.
317::
309::
273:s
221:s
212:A
203:2
183:c
179:I
80:)
74:(
69:)
65:(
51:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.