【量子力学/光学】単一電子トンネル効果により米粒大のメーザーを作成 - プリンストン大©2ch.net
掲載日：2015年1月16日
A team of scientists led by Dr Jason Petta of Princeton University has built a rice grain-sized microwave laser,
or maser, powered by single electrons tunneling through quantum dots – bits of semiconductor material that
act like single atoms.
This micromaser is a major step toward building quantum-computing systems out of semiconductor materials
; a battery forces electrons to tunnel one by one through two double quantum dots located at each end of
a cavity, moving from a higher energy level to a lower energy level and in the process giving off microwaves
that build into a coherent beam of light. Image credit: Jason Petta.
http://cdn4.sci-news.com/images/2015/01/image_2409-Micromaser.jpg
“It is basically as small as you can go with these single-electron devices,” Dr Petta said.
The device, described in the journal Science, uses about one-billionth the electric current needed to power a hair dryer.
It demonstrates a major step forward for efforts to build quantum-computing systems out of semiconductor materials.
“I consider this to be a really important result for our long-term goal, which is entanglement between quantum bits
in semiconductor-based devices,” said co-author Dr Jacob Taylor of the Joint Quantum Institute, University of
Maryland-National Institute of Standards and Technology.
The original aim was not to build a maser, but to explore how to use double quantum dots – which are two quantum dots
joined together – as quantum bits, or qubits, the basic units of information in quantum computers.
“The goal was to get the double quantum dots to communicate with each other,” said lead author Yinyu Liu of
Princeton University.
Because quantum dots can communicate through the entanglement of photons, the team designed dots that emit photons
when single electrons leap from a higher energy level to a lower energy level to cross the double dot.
Each double quantum dot can only transfer one electron at a time.
“It is like a line of people crossing a wide stream by leaping onto a rock so small that it can only hold one person.
They are forced to cross the stream one at a time. These double quantum dots are zero-dimensional as far as
the electrons are concerned – they are trapped in all three spatial dimensions,” Dr Petta said.
The scientists fabricated the double quantum dots from extremely thin nanowires (about 50 nanometers) made of
a semiconductor material called indium arsenide. They patterned the indium arsenide wires over other even
smaller metal wires that act as gate electrodes, which control the energy levels in the dots.
To construct the maser, they placed the two double dots about 6 mm apart in a cavity made of a superconducting material,
niobium, which requires a temperature near absolute zero, around minus 273 degrees Celsius.
When the device was switched on, electrons flowed single-file through each double quantum dot, causing them to
emit photons in the microwave region of the spectrum.
These photons then bounced off mirrors at each end of the cavity to build into a coherent beam of microwave light.
One advantage of the new device is that the energy levels inside the dots can be fine-tuned to produce light at other
frequencies, which cannot be done with other semiconductor lasers in which the frequency is fixed during manufacturing.
The larger the energy difference between the two levels, the higher the frequency of light emitted.
A team of scientists led by Dr Jason Petta of Princeton University has built a rice grain-sized microwave laser,
or maser, powered by single electrons tunneling through quantum dots – bits of semiconductor material that
act like single atoms.
This micromaser is a major step toward building quantum-computing systems out of semiconductor materials
; a battery forces electrons to tunnel one by one through two double quantum dots located at each end of
a cavity, moving from a higher energy level to a lower energy level and in the process giving off microwaves
that build into a coherent beam of light. Image credit: Jason Petta.
http://cdn4.sci-news.com/images/2015/01/image_2409-Micromaser.jpg
“It is basically as small as you can go with these single-electron devices,” Dr Petta said.
The device, described in the journal Science, uses about one-billionth the electric current needed to power a hair dryer.
It demonstrates a major step forward for efforts to build quantum-computing systems out of semiconductor materials.
“I consider this to be a really important result for our long-term goal, which is entanglement between quantum bits
in semiconductor-based devices,” said co-author Dr Jacob Taylor of the Joint Quantum Institute, University of
Maryland-National Institute of Standards and Technology.
The original aim was not to build a maser, but to explore how to use double quantum dots – which are two quantum dots
joined together – as quantum bits, or qubits, the basic units of information in quantum computers.
“The goal was to get the double quantum dots to communicate with each other,” said lead author Yinyu Liu of
Princeton University.
Because quantum dots can communicate through the entanglement of photons, the team designed dots that emit photons
when single electrons leap from a higher energy level to a lower energy level to cross the double dot.
Each double quantum dot can only transfer one electron at a time.
“It is like a line of people crossing a wide stream by leaping onto a rock so small that it can only hold one person.
They are forced to cross the stream one at a time. These double quantum dots are zero-dimensional as far as
the electrons are concerned – they are trapped in all three spatial dimensions,” Dr Petta said.
The scientists fabricated the double quantum dots from extremely thin nanowires (about 50 nanometers) made of
a semiconductor material called indium arsenide. They patterned the indium arsenide wires over other even
smaller metal wires that act as gate electrodes, which control the energy levels in the dots.
To construct the maser, they placed the two double dots about 6 mm apart in a cavity made of a superconducting material,
niobium, which requires a temperature near absolute zero, around minus 273 degrees Celsius.
When the device was switched on, electrons flowed single-file through each double quantum dot, causing them to
emit photons in the microwave region of the spectrum.
These photons then bounced off mirrors at each end of the cavity to build into a coherent beam of microwave light.
One advantage of the new device is that the energy levels inside the dots can be fine-tuned to produce light at other
frequencies, which cannot be done with other semiconductor lasers in which the frequency is fixed during manufacturing.
The larger the energy difference between the two levels, the higher the frequency of light emitted.
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2 ：Mogtan ★＠転載は禁止 ©2ch.net：2015/01/31(土) 21:26:29.49 ID:???
<参照>
Princeton University - Rice-sized laser, powered one electron at a time, bodes well for quantum computing
http://www.princeton.edu/main/news/archive/S42/13/37M75/index.xml?section=newsreleases
Semiconductor double quantum dot micromaser
http://www.sciencemag.org/content/347/6219/285.abstract
Kyoto University Research Information Repository: 低温サブゼミナール : 単一電子トンネリング
(Single Electron Tunneling)(低温,第40回 物性若手夏の学校(1995年度),講義ノート)
http://repository.kulib.kyoto-u.ac.jp/dspace/handle/2433/95619
<記事掲載元>
http://www.sci-news.com/physics/science-rice-grain-sized-maser-02409.html
Princeton University - Rice-sized laser, powered one electron at a time, bodes well for quantum computing
http://www.princeton.edu/main/news/archive/S42/13/37M75/index.xml?section=newsreleases
Semiconductor double quantum dot micromaser
http://www.sciencemag.org/content/347/6219/285.abstract
Kyoto University Research Information Repository: 低温サブゼミナール : 単一電子トンネリング
(Single Electron Tunneling)(低温,第40回 物性若手夏の学校(1995年度),講義ノート)
http://repository.kulib.kyoto-u.ac.jp/dspace/handle/2433/95619
<記事掲載元>
http://www.sci-news.com/physics/science-rice-grain-sized-maser-02409.html
3 ：Mogtan ★＠転載は禁止 ©2ch.net：2015/01/31(土) 21:30:05.99 ID:???
日も経ってるのであるかなーと思ってけっこう探したのですが
邦訳記事がまったく見当たりませんでしたm(_ _)m
邦訳記事がまったく見当たりませんでしたm(_ _)m
4 ：名無しのひみつ＠転載は禁止：2015/01/31(土) 21:35:58.23 ID:1vhGqZgA
日本復活へ…: http://youtu.be/JpTZQsbn0Rg
5 ：名無しのひみつ＠転載は禁止：2015/01/31(土) 21:36:26.55 ID:hUfD98nE
確率論の話が実物になると、イメージがわきにくくて違和感があるんだよね
6 ：名無しのひみつ＠転載は禁止：2015/01/31(土) 21:41:45.01 ID:FCr9VGid
>>3
英語のままの方が理解しやすいから気にすんなや
英語のままの方が理解しやすいから気にすんなや
7 ：名無しのひみつ＠転載は禁止：2015/01/31(土) 21:43:14.66 ID:m+HVNV0v
俺独自の研究の結果、電子は2個以上ないとレーザー発振は不可能
という結論にたどり着いた。
という結論にたどり着いた。
8 ：名無しのひみつ＠転載は禁止：2015/01/31(土) 21:59:35.89 ID:OooUfzNh
量子トンネルってＤＷＡＶＥのコンピューターもその理論使って種
9 ：名無しのひみつ＠転載は禁止：2015/01/31(土) 22:23:09.76 ID:EwBUua8X
10 ：名無しのひみつ＠転載は禁止：2015/01/31(土) 22:25:32.72 ID:TCJonvuL
11 ：名無しのひみつ＠転載は禁止：2015/01/31(土) 22:33:27.30 ID:tznbojsN
単一電池ってあまり使わないよね。
ストーブくらい？
ストーブくらい？
12 ：名無しのひみつ＠転載は禁止：2015/01/31(土) 22:33:53.60 ID:h5SQJaFj
13 ：名無しのひみつ＠転載は禁止：2015/01/31(土) 22:33:55.92 ID:RPomhmGi
量子ドットのメーザーより爆撃機を破壊できるレーザーを人類は求む。
14 ：名無しのひみつ＠転載は禁止：2015/01/31(土) 23:27:24.05 ID:a8Fs8ejr
韓国語でおｋ
15 ：名無しのひみつ＠転載は禁止：2015/02/01(日) 02:00:23.49 ID:YRI/BMvu
ぼくらーはーめざしだーでしょ
16 ：名無しのひみつ＠転載は禁止：2015/02/01(日) 09:09:37.17 ID:VFGFNy9m
フェイズドアレイメーザーが作れるな
17 ：名無しのひみつ＠転載は禁止：2015/02/01(日) 09:46:12.57 ID:9jRjAIY9
個人用フェーザー早よ！
18 ：名無しのひみつ＠転載は禁止：2015/02/01(日) 09:53:58.77 ID:1uGCYzaW
19 ：名無しのひみつ＠転載は禁止：2015/02/01(日) 10:13:35.22 ID:8VIWyT1q
アメリカでも米粒大rice grain-sizedって言うのか・・
麦粒かと思ったｗ
麦粒かと思ったｗ
20 ：名無しのひみつ＠転載は禁止：2015/02/01(日) 10:31:07.15 ID:JDW/r/Y4
米粒大ほどの巨視的なトンネル効果って凄いよな
21 ：名無しのひみつ＠転載は禁止：2015/02/01(日) 10:56:06.99 ID:VUh4y/M3
メーザー殺獣光線砲
22 ：名無しのひみつ＠転載は禁止：2015/02/01(日) 11:45:28.57 ID:uJMjSjSn
ちゃんとやれ
23 ：名無しのひみつ＠転載は禁止：2015/02/01(日) 11:53:46.13 ID:NLVOTygt
レーザー増幅したら量子ノイズでもつれが全部ぶち壊しになるのに量子コンピューターとか、脳みそわいてんのか
24 ：名無しのひみつ＠転載は禁止：2015/02/01(日) 12:47:27.02 ID:mYfH6wqb
メーザーとレーザーの違いを教えてください
25 ：名無しのひみつ＠転載は禁止：2015/02/01(日) 13:24:48.20 ID:LZe+TNEm
要はどういうこと？
26 ：名無しのひみつ＠転載は禁止：2015/02/02(月) 00:21:25.50 ID:yrqWsM9E
「米粒大」って主食の日本だからの言い回しだと思ってたが、英語でもrice grain-sized っていうんだな
27 ：名無しのひみつ＠転載は禁止：2015/02/06(金) 02:27:09.11 ID:3AXELcdv
>>21
東宝のは通称「メーサー」
東宝のは通称「メーサー」
D-Wave社の量子コンピュータは「本物」〜米研究者グループが「量子効果を確認」
http://internet.watch.impress.co.jp/docs/news/20130701_605845.html
Large-scale quantum chip validated
http://news.usc.edu/52818/large-scale-quantum-chip-validated/
http://news.usc.edu/files/2013/06/Lidar_Daniel.jpg
Quantum Computing
http://aurorawave.atspace.tv/?sop:v/Fls523cBD7E&RDFls523cBD7E https://i1.ytimg.com/vi/Fls523cBD7E/mqdefault.jpg
http://internet.watch.impress.co.jp/docs/news/20130701_605845.html
Large-scale quantum chip validated
http://news.usc.edu/52818/large-scale-quantum-chip-validated/
http://news.usc.edu/files/2013/06/Lidar_Daniel.jpg
Quantum Computing
http://aurorawave.atspace.tv/?sop:v/Fls523cBD7E&RDFls523cBD7E https://i1.ytimg.com/vi/Fls523cBD7E/mqdefault.jpg
