n***n
发帖数: 80 | 1 Kramers-Krönig relations in nonlinear optics
Journal Optical and Quantum Electronics
Publisher Springer Netherlands
ISSN 0306-8919 (Print) 1572-817X (Online)
Issue Volume 24, Number 1 / January, 1992
j*****[email protected]
Many thanks |
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x***u
发帖数: 6421 | 2 Could you explain the new "deconfined" quantum critical theory? |
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w****1
发帖数: 4931 | 3 As far as I understand the quantum critical theory is described by a CFT
that connects a Higgs phase to a Coulomb phase. It is described by the IR
fixed point of a (fined tuned) gauge theory rather than a Wilson-Fisher type
fixed point. "Simple" field theories are often the hardest to solve. Highly
supersymmetric field theories look complicated but are easy to solve.:) |
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w****1
发帖数: 4931 | 4 loop quantum gravity is nonsense.:)) |
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w****1
发帖数: 4931 | 5 Oh you mean THE deWitt.:D I never knew his first name. If you only care
about solving quantum field theories by themselves, susy is a simplification
. While you can't solve the harder problems, solving easier problems is
progress. You can't say you are fed up with it unless you have better ideas. |
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w****1
发帖数: 4931 | 6 To me swampland means consistent theories of quantum gravity that are not (
limits of) string theories. It's not obvious that the swampland is nonempty. |
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s*****7
发帖数: 55 | 7 我们实验室最近买了PPMS-VSM magnetometer (Quantum Design), 机器测出来的磁矩（
moment)的单位是emu，但我希望eumOe, 这样子算DC magnetic susceptibility的单位
才是emu/g. 而且我想算Magnetization in the unit of emuOe/mol or emuG/mol. 这
样才能跟理论值比较。 我想知道有什么办法可以让机器测的磁矩（moment)的单位是
eumOe。谢谢了！ |
|
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o********e
发帖数: 474 | 9 Quantum Field Theory
-A Modern Perspective
V.Parameswaran Nair
Springer
Hardcover
处理，看着给 |
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h***h
发帖数: 102 | 10 but why this has anything to do with quantum computer??? |
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s*******i
发帖数: 12823 | 11 只能用quantum computing来实现的算法
classical computer上不能实现 |
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h***h
发帖数: 102 | 12 why this can only be done on a quantum computer? |
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h***h
发帖数: 102 | 13 but why this has anything to do with quantum computer??? |
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s*******i
发帖数: 12823 | 14 只能用quantum computing来实现的算法
classical computer上不能实现 |
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h***h
发帖数: 102 | 15 why this can only be done on a quantum computer? |
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q**i
发帖数: 174 | 16 I got this off slashdot.org, http://cryptome.org/qc-grover.htm
it talks about a quantum computer that is capable of processing information
and algorithm simutanneously (parallel computing in its classic sense).
the following is an interesting example of what a QC can do:
=======begining of quote=========
By observing the carbon qubit of the EPR state, then, you force decoherence
and destroy the superposition; you had an even chance of observing a 0 or a
1,
but you could observe only one or the o |
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l**********n
发帖数: 72 | 17 Not so. You can first encode the information in the quantum state and then
control the measurement to get the information at another point. Such as the
EPR experiment, you could set the spin up state is that "The enemy is coming!"
and the spin down state to be "The rabbit is coming!" OK? :) When the
particles departed, they carries the entangled information. Then when the
particle reached the soldiers at point A and they saw the rabbit, they set
their communication tool to make the particle poin |
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l**********n
发帖数: 72 | 18 That's easy. That means particle is in an entangled state a|up>+b|down>, where
a, b are complex variables to include the phase. Then the particle impinges on
a highly polarized thin film with atoms all pointing to spin up, so |up>. The
interaction between the particle and thin film of atoms are v(r), therefore,
the possibility of flipping up is
/(+), so, I could make the
interaction perferable to |up> state.
Don't confuse too much with the quantum state |
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q*****m
发帖数: 73 | 19 The answer could be found on P333 of Schiff, Quantum Mechanics.
You can integrate over the coordinate of the electron first,
use some trick:
\int e^{-i q.r1} / r1 dr1 <--- q and r1 are vectors here
= lim_{\alpha->0} 4 \pi/q
\int_0^{\infinty} sin(q r1) e^{-\alpha r1} dr1
=4 \pi/q^2
Then the Total Cross-section is given by
4 \pi |c|^2 e^2 /q^2
\int( exp(i \vec{q r2}) -1) <2p|1s> dr1 |
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f*******d
发帖数: 339 | 20 EPR.
Consider instead of quantum mechanics, you have classical
mechanics,
you have two spins correlated, and you don't know the value.
After the measurement,
you instantly know the other spin too:-) However, it seems
that no one
argues that there is any problem with relativity in
classical theory?
So what's the difference? The difference is, in classical
mechanics,
the state does not change during the measurement, you "know"
the
spin of the other particle, but it is simply by inference,
or in
ot |
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|
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l**********n
发帖数: 72 | 23 Any one could tell me what's the typical dot size? Is it around (500 nm)^3 or
even less? What's the separations between dots? What is the electron diffusion
length?
What are the growth techniques for semiconductor quantum dots? Normally what
are the materials? |
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g**h
发帖数: 15 | 24 In self-assembly semiconductor quantum dots, the literal size is around
10~50 nm and height around 5~10 nm. But it's very difficult to measure
the exact dot size and shape experimentally. The areal dot density is
around 10^9 cm-2 to 10^11 cm-2, you can use this data to estimate the
average separation between different dots. I don't know electron diffusion
length, give me some clue.
The most common growth technique for QDs is the strain-driven self-
assembly technique. For example, the lattice co |
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l**********n
发帖数: 72 | 25 It seems there are many research groups on LEDs, including polymer, and
semiconductors. What's the quantum efficiency of these LEDs? What's the
world's best record?
I am familiar with Yang's paper and group. The theory is still not clear. He
chose the proper material and it will be quite amazing if he grows InP
nanowires with the same alignment.
Remember to read my post on human retina. Tell me what you think.
most
stoichiometric
give
the
LEDs,
I |
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l**********n
发帖数: 72 | 26 Just imagine each one of us is like a processing unit with local memory. The
law of nature is like the different algorithms of searching, compressing, self
expressing and self assembling, etc. Another version of the matrix. :)
"Nature and location of quantum information", Robert B. Griffiths, Phys. Rev.
A 66, 012311 (2002)
"Computational Capacity of the Universe", Seth Lloyd, Phys. Rev. Lett. 88,
237901 (2002) |
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a*****c
发帖数: 3525 | 27 如果你做过，跟什么东西比较？怎么测？有文献吗？能否给指点一下？ 谢谢！
合成了一些东西，带荧光，想测一下quantum yield. |
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w*******y
发帖数: 60932 | 28 Decent deal for Quantum of Solace for Xbox 360 for $8.99 and free shipping
at Newegg
Link:
http://www.newegg.com/Product/Product.aspx?Item=N82E16874117066
Next lowest is on Amazon for $12.66.
*Sales taxes for CA, TN and NJ. Additional fees may apply to shipments to
AK, HI and PR
I would pick it up, but I've already built up a backlog from the BF and CM
sales. Hopefully this helps someone out.
|
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w*******y
发帖数: 60932 | 29 Been searching for decently priced BD-R media, the Optical Quantum brand has
been getting pretty good reviews on the Egg. These have now dipped below
the $1.00 a disc price with todays recent sale (bummer, I bought some
yesterday!).
Anyhow, here's the deal:
25pack spindle of 25gb BD-R's rated at 4x (yet many reviews say they do
higher w/o any problems. YMMV).
Price: $22.50
Shipping: FREE
Tax: depends on location.
This puts the BD-R's at $0.90/disc (before taxes). I paid $1.20/disc
yesterday (aft... 阅读全帖 |
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w*******y
发帖数: 60932 | 30 Newegg currently has the Optical Quantum 25GB 4X BD-R 25 Packs Logo Top Blu-
ray Disc Model OQBDR04LT-25 for only $19.99 with free shipping (limit 5).
An even better deal if you just got one of those $25 off $50 new customer
coupons from them.
Link:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817607025
|
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w*******y
发帖数: 60932 | 31 Amazon has the Finish Quantum 45 count on sale for $10.09 when you use
subscribe and save. Use code HOUSERBI at checkout for an extra 15% off,
which brings it down to $8.31! And of course, shipping is always free with
subscribe and save.
Link:
http://www.amazon.com/gp/product/B004S0BV06/ref=ox_sc_sfl_title
|
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w*******y
发帖数: 60932 | 32 Cigars International's Deal of the Day is a Colibri Quantum Radius Torch
Lighter + Cutter:
http://www.cigarsinternational.com/html/spec_ncm.asp?scSlide=2
for $12.50 plus shipping. It retails for $87.00 although you can find
them on eBay for about $38. Either way it's a great deal for a cigar
lighter from a very good company.
|
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w*******y
发帖数: 60932 | 33 Ok. I checked this deal before posting. It was listed on Amazon earlier
today at 6.99 New Free shipping but this deal but it is no longer available.
Besides you had to buy at least $25 without prime to get the shipping. The
Amazon deal is now dead. Also I searched and others had threads for around
this price and not until Black Friday.
I found this deal on Newegg.com It is current and it is a NEW Quantum of
Solace XBOX 360 game which is currently available. Also they have this
listed on Ebay as ... 阅读全帖 |
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w*******y
发帖数: 60932 | 34 Just wanted to get this back out there again, rather than update an old
posting, but now at a better price. Now about .50per BD-R disc.
Newegg has the BD-R Media 50 Pack 25GB 4X $24.79 AC + FS Newegg Optical
Quantum Vinpower Digital Blu-ray Discs
Link: Link:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817607054
20% off code Code: EMCJJGK38 -
|
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g******y
发帖数: 2517 | 36 Char-Broil Quantum Infrared Urban Gas Grill with Folding Side Shelves, 42%
Off
http://amzn.to/yjRWiN |
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w*******y
发帖数: 60932 | 37 On sale for $150 on ebay daily deals
cgi.ebay.com/LG-Quantum-C900-Unlocked-Phone-Windows-7%2C-QWERTY-Keyboard-5-
MP-Camera---BLACK/160688247427?_trksid =p1468660.m2000037
This was $250 6 months and got pretty good feedback so this shouldn't be too
bad.
Few highlights:
- Full QWERTY keyboard
- unlocked
- 5 MP camera
It runs Windows phone which should fine for basic usage (web browsing,
texting, taking photos).
Checked completed listing for used ones sold recently and they go from $100-
$120 dep... 阅读全帖 |
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w*******y
发帖数: 60932 | 38 Finish Quantum (facebook required)
Lanacane(TM) Anti-Chafing Gel
American baby free subscription
Baby Talk free subscription
Purex
Oatmeal
Lacoste
Astroglide Natural
Emergen-C vitamin
Prilosec OTC
Link:
http://iway.org/9573701
|
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i******r
发帖数: 1175 | 39 鱉完成的這量子計算模擬落後有10年了吧。量子計算領先梯隊裏沒有中國團隊。沒有一
樣重要研究成果是中國人的。
Timeline[edit]
Main article: Timeline of quantum computing
In 1959 Richard Feynman in his lecture "There's Plenty of Room at the Bottom
" states the possibility of using quantum effects for computation.
In 1980 Paul Benioff described quantum mechanical Hamiltonian models of
computers[57] and the Russian mathematician Yuri Manin motivated the
development of quantum computers.[58]
In 1981, at a conference co-organized by MIT and IBM, physicist ... 阅读全帖 |
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q**w
发帖数: 782 | 40 http://www.technologyreview.com/view/509106/best-of-2012-chines
Best of 2012: Chinese Physicists Smash Distance Record For Teleportation
The ability to teleport photons through 100 kilometres of free space opens
the way for satellite-based quantum communications, say researchers
Teleportation is the extraordinary ability to transfer objects from one
location to another without travelling through the intervening space.
The idea is not that the physical object is teleported but the information
th... 阅读全帖 |
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z**********g
发帖数: 16 | 41 继续发表有关斥力子的文章，请指正。
“斥力子理论”对物理学的影响1
庄一龙
近年来，由中国学者创立的“斥力子理论”，经过中国科学院《科技促进发展》《
科技成果管理与研究》、《科技中国》、《中国科技财富》、《中国科技成果》等主流
科技杂志报导后，引起了学术界广泛重视。那么，这一理论究竟有那些观点震动了学术
界，值得人们如此关注呢？
“斥力子理论” 是一种新物质作用理论，实际上也是一种物理哲学理论。它的代
表性文章是《论“斥力子”的存在及其意义》，另外还包括《相对性效应和牛顿定律的
本质》、《物理学中精细结构常数的理论推导与解释》等几十篇论文。同牛顿的苹果从
树上掉下来的万有引力理论相对应，这是一个可称作“苹果如何转移到树上去的‘万有
斥力’理论”。该理论认为，地面的物体一旦动起来，不管方向如何，都具有一种挣脱
地球引力的能力，就好象物体吸收了一种对抗万有引力的物质那样。“斥力子理论”把
普朗克能量子看作是一种对抗引力的实物粒子，称它为“斥力子”，并认为物体运动状
态的改变就是由于吸收或释放斥力子造成的。
在思维方法上，它有两个根本突破：其一,是把抽象的能量概念实物化，使能量有
一个实物载... 阅读全帖 |
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发帖数: 1 | 42
https://www.technologyreview.com/s/609451/ibm-raises-the-bar-with-a-50-qubit
-quantum-computer/
Intelligent Machines
IBM Raises the Bar with a 50-Qubit Quantum Computer
Researchers have built the most sophisticated quantum computer yet,
signaling progress toward a powerful new way of processing information.
by Will Knight November 10, 2017
IBM's 50-qubit machine.
8
IBM established a landmark in computing Friday, announcing a quantum
computer that handles 50 quantum bits, or qubits. ... 阅读全帖 |
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w*****1
发帖数: 220 | 43 Dear Readers,
We are happy to present the first five papers that are published in our
new, open access journal, Physical Review X. These papers, together with
others that are to be published in the coming weeks into September, will
constitute the first issue of the journal. Under PRX's open access
publishing model, they are free for you to read and use.
We are very encouraged by the breadth of their topical spread. It ranges
from the well-established field of atomic, molecular and optica... 阅读全帖 |
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l*****o
发帖数: 19653 | 44 看看这篇文章吧（放狗搜的）：
http://www.economist.com/node/21548151
QUANTUM effects are vital to modern electronics. They can also be a damnable
nuisance. Make a transistor too small, for example, and electrons within it
can simply vanish from one place and reappear in another because their
location is quantumly indeterminate. Currents thus leak away, and signals
are degraded.
Other people, though, see opportunity instead. Some of the weird things that
go on at the quantum scale afford the possibility of doin... 阅读全帖 |
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a*******l
发帖数: 2353 | 45 ☆─────────────────────────────────────☆
quantum1986 (quantum) 于 (Fri Dec 7 01:48:26 2012, 美东) 提到:
蔡伯澄先生讲心意的视频
http://v.youku.com/v_show/id_XNDM4OTUzMTI4.html
还是有料的
☆─────────────────────────────────────☆
wokaowokao (Sela'ma ashal'anore!) 于 (Fri Dec 7 13:39:01 2012, 美东) 提到:
蛮好的，大部分老师教确实不讲这个。自己不练，也体会不到这个。就是一个气与力合
就是单把有一点点乍肘，不过可能是解说重点不在那里，随意做的
☆─────────────────────────────────────☆
bigtempler (For the Lich King!) 于 (Fri Dec 7 16:06:13 2012, 美东) 提到:
一身雪练也似的白肉
太性感了
☆──────────────... 阅读全帖 |
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f***y
发帖数: 4447 | 46 http://bbs.netbig.com/thread-2702025-1-2.html
一期9篇研究性文章，1/3是科大的，郭光灿组两篇，潘建伟组一篇
另外在news and views还有一篇点评潘建伟的工作
etters
Experimental investigation of the no-signalling principle in parity–time
symmetric theory using an open quantum system - pp642 - 646
Jian-Shun Tang, Yi-Tao Wang, Shang Yu, De-Yong He, Jin-Shi Xu, Bi-Heng Liu,
Geng Chen, Yong-Nan Sun, Kai Sun, Yong-Jian Han, Chuan-Feng Li & Guang-Can
Guo
doi:10.1038/nphoton.2016.144
The violation of the no-signalling principle — information can be
tr... 阅读全帖 |
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Y****N
发帖数: 8694 | 47 【 以下文字转载自 Faculty 讨论区 】
发信人: Highly (高妹), 信区: Faculty
标 题: 我为尹希教授做的专访
发信站: BBS 未名空间站 (Wed Sep 23 14:31:24 2015, 美东)
Interview with Dr. Xi Yin
--- By Fiona Rawsontile, Sept 2015
This interview was inspired by an earlier interview of Dr. Yin I saw on the
Internet, which made me think that we can’t expect someone who normally
writes for entertainment to understand a physicist. To “provoke” a
scientist, we need another scientist. So I volunt... 阅读全帖 |
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H****y
发帖数: 2992 | 48 Interview with Dr. Xi Yin
--- By Fiona Rawsontile, Sept 2015
This interview was inspired by an earlier interview of Dr. Yin I saw on the
Internet, which made me think that we can’t expect someone who normally
writes for entertainment to understand a physicist. To “provoke” a
scientist, we need another scientist. So I volunteered (to myself) and sent
an invitation to Dr. Yin, who was recently promoted to Professor in Physics
at Harvard Uni... 阅读全帖 |
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S*******t
发帖数: 3956 | 49 （作为年仅31岁就晋升哈佛正教授的青年才俊，尹希教授最近得到了很多关注。其中一
篇关于他的专访进入了一名同是美国大学华裔教授的女科学家的视线。因为觉得这样的
采访不过瘾，她突发奇想，想亲自采访一下尹希。于是就有了这个我们今天看到的两名
科学家之间的对话。这位女教授使用了化名，这是她出版自己几部科幻小说的笔名。对
，没错，这位女教授同时也是一个女文青，已经写了几本书，还都是英文，Amazon 就
能买到。感兴趣的不妨找来看看。很可能有一天，她也会成为传奇式的人物。那今天这
篇采访就会成为另一段佳话。）
Interview with Dr. Xi Yin
--- By Fiona Rawsontile, Sept 2015
Translated by Slow Rabbit
This interview was inspired by an earlier interview of Dr. Yin I saw on the
Internet, which made me think that we can’t expect some... 阅读全帖 |
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W*******s
发帖数: 18705 | 50 最近对我以前的渔具玩得非常厌烦了，我也没多闲钱烧日货，在Ebay上倒腾卖出买进，
连BassProShop，TacklewareHouse的零买，搞了6条杆子，六个轮子，玩的是Down
Grade,基本倒贴了没多少钱，把装备翻新了一下。现在主打轮子是Quantum，Daiwa，杆
子是黑胡萝卜杆--我拿过得最轻的杆子（橘红色的也差不多，不能消化这颜色），
Quantum Smoke。卖好几年前的高级轮子，Daiwa TDZ,再把新轮子解体洗涤重新上油/腻
，我发现，尼玛所有的轮子内部结构都几乎一样，任何Low Profile Baitcast轮子我基
本上不用看图就能拆装。目前美国市场上卖的淡水上手轮分中国，韩国，日本，美国制
造。中国，韩国制造的牌子有Abu，Quantum，Okuma，Lews，BassProShop，Pfluger，
Pinnacle，某些Shimano，Daiwa低端轮子，等等占大部分的市场。这些轮子的品牌多为
个幌子，轮子基本上都是“保密”的相同中国韩国工厂生产的，很多零件都是通用的，
大同小异。打开Lews Tournament Pro，Quantum Sm... 阅读全帖 |
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