Tunneling is generally regarded as a quantum phenomenon.\u00a0 For example, electrons can tunnel through a thin insulating barrier.\u00a0 Electromagnetic waves can also tunnel through gaps.\u00a0 In collaboration with University of Manitoba’s Prof. \u00a0John Page, we have demonstrated for the first time that sound waves can also exhibit tunneling [1,2].\u00a0 This was done by first constructing a photonic crystal consisting of tungsten carbide spheres (0.8 mm in diameter) arranged in face-centered-cubic crystalline structure.\u00a0 The whole structure was placed in water.\u00a0 A photonic bandgap is predicted through first-principles calculation with the mid-gap frequency of ~0.8 megahertz.\u00a0 Sound transmission along the [111] direction of the crystal was measured.\u00a0 It was seen that the measured transit time of a sonic wavepacket, with its dominant frequency in the gap regime, can be even shorter than that predicted for tungsten carbide (of similar thickness) when the photonic crystal is more than 8 mm thick.\u00a0 This can be explained by the fact that tunneling is essentially governed by the uncertainty principle, so the transit time across the barrier should be independent of its thickness (although the magnitude of the transmitted pulse packet decreases exponentially with thickness).\u00a0 For thick barrier it means an extremely “fast” propagation.\u00a0 This has indeed been confirmed experimentally.\u00a0 However, there are intrinsic differences between electron tunneling and the tunneling of sound, which was also observed.<\/p>\n
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Key Publications:<\/strong><\/p>\n Tunneling is generally regarded as a quantum phenomenon.\u00a0 For example, electrons can tunnel through a thin insulating barrier.\u00a0 Electromagnetic waves can also tunnel through gaps.\u00a0 In collaboration with University of Manitoba’s Prof. \u00a0John Page, we have demonstrated for the first time that sound waves can also exhibit tunneling [1,2].\u00a0 This was done by first constructing … Continue reading Ultra sound tunneling<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[5],"tags":[],"_links":{"self":[{"href":"https:\/\/sheng.people.ust.hk\/index.php?rest_route=\/wp\/v2\/posts\/252"}],"collection":[{"href":"https:\/\/sheng.people.ust.hk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sheng.people.ust.hk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sheng.people.ust.hk\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sheng.people.ust.hk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=252"}],"version-history":[{"count":3,"href":"https:\/\/sheng.people.ust.hk\/index.php?rest_route=\/wp\/v2\/posts\/252\/revisions"}],"predecessor-version":[{"id":286,"href":"https:\/\/sheng.people.ust.hk\/index.php?rest_route=\/wp\/v2\/posts\/252\/revisions\/286"}],"wp:attachment":[{"href":"https:\/\/sheng.people.ust.hk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=252"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sheng.people.ust.hk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=252"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sheng.people.ust.hk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=252"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}\n