Research press release


Nature Materials

How heat dissipates in cryogenic electronics



今回Austin Minnichたちは、極低温電子デバイスで実現される非常に低い温度(約-260℃)の場合、通常とは全く異なる「フォノン黒体放射」と呼ばれる機構で熱放散が起こることを見いだした。フォノン黒体放射は、加熱に起因する振動が結晶と相互作用せずに放射を放出するときに起こる。この新しく観測された熱放散機構はかなりの自己加熱につながるため、極低温電子デバイスの最低動作温度は制限され、それによって実現可能な最小感度が制限される。

Electronics that operate at extremely low temperatures dissipate heat via a different mechanism than conventional electronics, reports a study in Nature Materials. This is the first observation of this mechanism, which results in significant self-heating, and could potentially impact the ultimate sensitivity achievable in cryogenic electronics, such as those used on space crafts.

Such cryogenic electronics are used in high-accuracy low-energy and low-noise applications and understanding how their components dissipate heat is of paramount importance, as both heat dissipation and mechanisms of self-heating can result in the degradation of a device’s performance. Under normal circumstances, and at a temperature of approximately 25 degrees Celsius, heating causes the crystals, which make up electronic components, to vibrate. Heat escapes through the damping of these vibrations at defects and interfaces of the crystals.

Austin Minnich and colleagues find that, at the very low temperatures achieved in cryogenic electronics (approximately -260 degrees Celsius), heat dissipation occurs by a completely different mechanism, called ‘phonon black-body radiation’. Phonon black-body radiation occurs when vibrations, caused by heating, emit radiation without any interaction with the crystals. This newly observed mechanism of heat dissipation results in considerable self-heating, which limits the minimum temperature that these electronics can operate at. This then limits the minimal achievable sensitivity of cryogenic electronic devices.

doi: 10.1038/nmat4126


メールマガジンリストの「Nature 関連誌今週のハイライト」にチェックをいれていただきますと、毎週各ジャーナルからの最新の「注目のハイライト」をまとめて皆様にお届けいたします。