Spectroscopy of a black hole and its horizon entropy

The idea of Isolated and Dynamical Horizon theory was first worked out by Heyward in 1994. He derived the complete definition of a marginally null surface that is trapped on a black hole horizon.

A few years later Ashtekar and his colleagues re-wrote the same theory in the language of Ashtekar- Sen variables. Before this development Rovelli has argued that a black hole entropy should be proportional with its horizon area. Lee Smolin linked loop quantum gravity to topological field theory and argued that a black hole should be described by a Chern Simon’s action.

Later on, Krasnov based on all the above mentioned ideas argued the derivation of a black hole entropy from the counting of puncture states. A ‘sequence’ of punctures on a horizon explains the wave function of the horizon. Being a sequence, the punctures are ordered and this make them distinguishable. However, there is no physical evidence why should one restricts the wave functions into a sequence and not a set of punctures in which there is no generic order, thus no distinguishability.

Given this in the quantum horizon theory, I noticed an internal degeneracy in the nature of area operator. Since the area eigenstates are insensitive to the completely tangential edges residing on the horizon, the edges describing a quantum surface carries a local distinguishability. The complete spectrum of area provides the Bekenstein-Hawking entropy, which using Olaf Dreyer’s conjecture it becomes consistent with the evaporation of minimal area cell with the corresponding area of the highly damping quanta.

This proposes a kinematical picture for defining a quantum horizon via spin foam models, however the dynamics of such a model has not yet initiated to be studied. . A new value was devoted to the Immirzi parameter. Considering the full spectrum of area and using the semi-classical conjecture that on a black hole the horizon area and the hole energy are proportional

I noticed a strong amplification in some selected frequencies radiated away from a black hole due to its horizon fluctuations. The full spectrum of a black hole radiation was extracted and the bright lines in the spectrum turn out to be unblended and narrow enough to become observable.

Josephson and Feynman in low temperature!

We recently calculated noise power spectrum due to the presence of magnetic impurities in a Josephson junction explicitly, using Feynman diagrams. The long paper includes all details of integrations and calculations.

The results were presented is written in a way that serves as a good source to understand step by step the details of analysis of decoherence in mesoscopic superconducting systems that includes the Kondo effect through the Coulomb interactions Feynman diagrams in low temperature.

It was recently published in PRB in 19 pages.

Strom in Waterloo, Ontario

I took this photo tonight from my balcony at Waterloo, where I was spectator of a rain storm. after many attempts I finally succeeded to take this shot from a lightning.

Irrelevant news from nature to loop quantum gravity

Today I read this article from BBC that LHC results put supersymmetry theory in trouble.

The results do not rigorously demonstrate anything because Strings can exist without low-energy supersymmetry of Loops with supersymmetry. I do not understand why the community of loop quantum gravitists are this much happy about it?! Its certainly bad news for preliminary string theory, but how about loop quantum gravity? Loop Quantum Gravity does not rely on superstring theory but it can certainly handle that. Loop quantum gravity certainly is an alternating theory, but there are many other candidates to seek for using the foundations of quantum mechanics.

But certainly this result is without doubt so important to be argued for a long time between experts.

The paper of Kondo noise ...

I and Frank worked on it, was accepted for publication in Physical Review B in the third week after submitted. This is a new score in short-time reviewing process perhaps because we paid it off from working on it for almost a year!

If you are working on the critical current noise in superconducting materials or in general you deal with superconducting qubits or SQUIDS, reading this paper is highly recommended.

You will find in it a good analytical approach to understand the complicated physics of a magnetic impurity inside a Josephson junction. With the consistency it provides with the Wilson type renormalization group method so far was used in the Kondo community, it equips us to study the critical current noise in a tunnel junction in the presence of a few free Oxygen molecules inside the tunnel junction oxide layer.

Theory Canada 6 in the city of Corner Brook in Newfoundland, Canada was exciting and interesting. The nature of the city is unique and the core idea of the conference was intriguing: some of the Canadian theorists who due to the wide geography of this country cannot meet each other in a regular base gather in one place a few days before CAP conference and collaborate on exchanging ideas and thoughts.

Mohammad H. Ansari

Noise and microresonance of critical current in Josephson junction

Along with Frank Wilhelm I enjoyed working on the noise study of a Josephson junction. The results appeared today at

arxiv.org/abs/1106.4794

We analyze the impact of trap states in the oxide layer of a superconducting tunnel junctions, on the fluctuation of the Josephson critical current, thus on coherence in superconducting qubits.

Two mechanisms are usually considered: the current blockage due to repulsion at the occupied trap states, and the noise from electrons hopping across a trap. We extend previous studies of noninteracting traps to the case where the traps have on-site electron repulsion inside one ballistic channel.

The repulsion not only allows the appropriate temperature dependence of 1/f noise, but also is a control to the coupling between the computational qubit and the spurious two-level systems inside the oxide dielectric.

We use second order perturbation theory which allows to obtain analytical formulae for the interacting bound states and spectral weights, limited to small and intermediate repulsions.

Remarkably, it still reproduces the main features of the model as identified from the Numerical Renormalization Group.

We present analytical formulations for the subgap bound state energies, the singlet-doublet phase boundary, and the spectral weights.

We show that interactions can reverse the supercurrent across the trap.

We finally work out the spectrum of junction resonators for qubits in the presence of on-site repulsive electrons and analyze its dependence on microscopic parameters that may be controlled by fabrication.

Meet other creatures

Meet them in these scales of a meter:

• 10^-35:  Quantum gravity domain. Planck's length.
• 10^-30:
• 10^-28:
• 10^-24: Neutrino
• 10^-21:  Perons, the ingredients of quarks.
• 10^-18: Quarks. Electron cores.
• 10^-15: Protons.
• 10^-14: size of light nuclei.
• 10^-12: Gamma ray wavelength. 
• 2*10^-12: electron Compton wavelength.
• 5*10^-12: X-ray wavelength.
• 2.5*10^-11: distance between two Hydrogen atom nuclei.
• 3.1*10^-11: distance between two Helium atom nuclei. 
• 7.0*10^-11: distance between two Carbon atoms nuclei.  
• 10^-10: distance between two Sulfure atom nuclei.
• 5*10^-10: width of Protein alpha Helix.
• 10^-9 (1 nano meter): Carbon nanotube.
• 2*10^-9: the smallest transistor gate of microprocessor.
• 3*10^-9: thickness of DNA.
• 10*10^-9: the width of cell membrane.
• 50*10-9: ultraviolate wavelength.
• 90*10^-9: HIV.
• 300*10^-9: Violate wavelength.
• 500*10^-9: largest virus.
• 600*10^-9: red light wavelength.
• 7*10^-6 (7 micrometer): red blood cell.
• 10*10^-6: infrared wavelength. Fog droplet. White blood cell. 
• 50*10^-6: Pullen grain. Silt particle. 
• 10^-4 (a tenth of milimeter): smallest things visible to naked eyes. Width of human hair.
• 2.5*10^-4: human egg. 
• 3*10^-4: computer pixel.
• 5*10^-4: salt crystal grain. Thickness of human skin. Largest bacteria. Pencil lead.
• 7*10^-4: thickness of credit card. 
• 10^-3: Ant. Sesame. etc. 

The Fritz London Prize 2011

is happy to hear the Fritz London Prize - highest award in low temperature physics after the nobel - is awarded to Hans Mooij in recognition for his experimental contributions to the understanding of nonequilibrium superconductivity, Josephson flux qubits, etc; at the same time to Gerd Schön in recognition of his theoretical contributions to the understanding of superconductivity in mesoscopic systems, including charge qubit; as well as to Humphrey Maris in recognition for his original theories and experimental discoveries in liquid helium, concerning phonons, Kapitza resistance, levitation, nucleation, electron bubbles and vortex imaging.

Conference Announcement NCMT 2011

Another major event in the region of South Western Ontario for the community of nanostructure phyicisits:

International Conference on Frontier Topics in Nanostructures and Condensed Matter Theory
March 9-11, 2011at Western

URL: http://ncmt2011.uwo.ca/

The Kondo theory

Additional unwanted qubits in a phase qubit due to the Kondo effect.
Simmonds et.al. Phys. Rev. Lett 2005 

The Kondo effect is one of the interesting features of low temperatur physics where temperature is seen not to play as a smoother, instead it ruines the results taken from perturbation theory.   Last Monday I presented a talk titled "the Kondo effect" in a Colloquium at the Institute for Quantum Computing IQC in Waterloo.  It was a good opportunity to face with some interesting questions and comments...

In this talk I presented two exotic behavior of electron in low temperature, one in a quantum dot, and the second in the Josephson junction between two superconductors.  In a quantum dots I explained the Kondo plateaus predicted in 1988 by Glazman and Raikh in JETP Lett. and they observed by van der Wiel et.al. Science 2000. In the second half, I explained how this effect can causes the presence of additional unwanted qubits interacting with the computational qubit. And finally our recent idea of how to suppress them to prevent errors on computations... 

How much snow

In the last three weeks there was about 2 meters of snow falling over London Ontario that caused the University to be closed for 4 days and the city buses not to operate for almost two days, due to the heavy load of snow on roads.


How much this city became heavier then? 


With the area of almost 400 (km^2), so the volume of snow is 0.8 billion (m^3). The mass density of freshly fallen snow is around 10% of that of water, let let be it 100 (kg/m^3).


So the total mass of the snow is huge: 80 billions (kg). 


This is equal to the mass of a near-Earth asteroid that caused a brief period of concern in December 2004 because initial observations indicated a small probability that it would strike the Earth in the year 2029!


How much power does this mass create?


If we consider the speed of rain droplets is a few meters per second, let us consider the speed of snow is at least 0.1(m/s), which produces the kinetic energy 1/200 (J/kg).  This much snow fell on the city in 4 days therefore the rate of falling was 80 billions kilograms per four days, or 200,000 kg/s. The total power is 1000 Watts.


This snow generated 5% of the solar power radiated by sun over this city.
    

Met him!

I remember last month in June, after staying up all night long at Student Life Center (SLC) of UWaterloo reading a paper on Gamma ray bursts and another one on noise in Josephson junctions, and rederiving all equations in them, I felt have no energy to walk 4km back home at 4AM. For the first time I slept on a sofa, it was not in fact a sofa it was quite I'd call a "recliner". In the middle of night this center is the only place open to students 24/7 for gathering, dancing, eating, drinking, listening, talking, studying, etc.

I woke up around 10 AM with freshly brewed coffee smell in the area. After I washed and had the best coffee with a big muffine, I went out to stretch and walk back home to take a shower. Right in front of my eyes I saw two bodygurads and Barak Obama. He was 2 meters away from me, coming out of a door and about to get into a car and there was nobody around. I was stoned to see this scene and thought I am dreaming. THe car door was open but before he gets into the car, he noticed my astonishment and stepped forward for a meter bending toward me and said hello, I am Barak, who are you? I was confused and totally mixed up. I said my name in the format I wrtite it on scientific papers: I said I am Mohamamd H. Ansari. He laughed and said "nice to meet you Mr. Mohammad H., What is the H. stands for?" and I said "Hossein". He laughed and said: "we have a name in common. Have a nice day"

On the way back home I could not believe what did I see and was reviewing the moment and laughing at how I introduced myself, it was so awkward! :)

Updates, December 2010: Since then I checked the news many times and there is nothing in the univerity news and publicity about the visit of the preseidnet from a random university. I am not surprised to hear today that the chair of our university has been promoted by the Queen Elizabeth to serve as the governor Gerneral of Canada, which is the federal representative of the Canadian/British monarch, i.e. the representatitive of the Queen in my country. Did the visit have anything to do about this news? I never know.

QISS 2010

The wonderful QISS 2010 workshop was definitely a success for the organizer Institute. We saw the most modern form of qubits in semiconductors, superconductors, and the buckyball fullerenes. More information can be found in here, where the talks are supposed to become available online soon.

Quantum Amplification Effect on black holes

Black holes radiate.

But recently it is shown they even more radiate!

In fact when their horizon fluctuates, they radiate on two or three frequencies that are heavily resonated, like a quantum amplifier.

These lines are at the range of frequency sensitivity that INTEGRAL may become able to find them. Perhaps we have observed them and do not recognize them as black hole QAE lines.

These lines could be foud in evenly or unevenly spaced fashion. in fact, Yakov Bekenstein and Viatcheslav Mukhanov predicted these lines (if are more than two) are exactly evenly spaced. With the support of theories that predict the spectrum of area scaling with the square-root of integers, we predicted they must be found in an unevenly-spaced fashion.

Details can be found in my recent Physical Reviews D paper...



This figure illustrates a quantum black hole horizon in the vicinity of a null boundary (the black sphere). In other words, you see a black hole as the interior black sphere underneath a discrete shell (the outer shell) that represents the hole's horizon area fluctuations.

The spectrum of a black hole radiation should be discrete, intense, and narrow line on top of weak the Hawking radiation.

The search for these lines in observational data is continued...

How to work with jpeg2ps software in Windows

How to work with jpeg2ps software in Windows:

1- After installing GSView (read here for instruction), download jpeg2ps from here, (thanks to sourceforge.com!)

2- After downloading is finished, click on the file and install the software. Note at what folder it's going to be installed. Its default location is usually at "C:\Program Files\GnuWin32\"

3- (Copy and) paste a JPEG, which you want to convert it into eps, into "C:\Program Files\GnuWin32\bin".

4- On Windows "Start" click on "Run" and write in its empty box "cmd". A black DOS window will appear inside which a default directory is written, usually it is "C:/Program Files/Username>". Each time you write "cd.." in front of the ">" and enter this folder goes one root backwards, so by repeating this you can go back to "C:>". Write "cd Program Files\GnuWin32\bin" or "cd [The "bin" folder address where you installed jpeg2ps at]. Now you are where the software jpeg2ps is! (If you are DOS expert you know how to write shortcut.)

5- Write "jpeg2ps" and you'll see the option menu. It is time now to actually convert a sample picture. Assume the file "sample.jpeg" (which is located at C:\Program Files\GnuWin32\bin) should be converted to EPS.

6- Write "jpeg2ps sample.jpeg > filename.eps". Doing this will create the file "filename.eps" in the folder C:\Program Files\GnuWin32\bin. This will be your desired eps file. You can change the resolution as well as other options.

Enjoy!


More information:
How to convert quality jpeg images into eps. (Guage Invariance)

Timing backwards

Let's assume we are watching 10 seconds of a basketball game. It is right at the moment when two players are standing near the basket and the ball is passed from one player to the other who reside under the basket. This player after, grabbing the ball, turns about his waist and shoots the ball into the basket such that the ball enters into the net from its below. We no longer see the game.

Now consider time goes backwards. The ball enters the basket from above, one player grabs it and passes it to the farther player. Consider the way how the players act is such that we cannot distinguish the difference between the first scenario and the second one only by watching their action.

It seems in the lack of the rest of the play, we cannot distinguish between these two degenerate scenarios. However, there is a tiny difference between the two that breaks the degeneracy. In fact, by noticing that we can distinguish between the correct and the backward time directions. Guess what is the point?

Mohammad H. Ansari

A new solution to the statistics of hard elongated objects

A new solution to the statistics of hard elongated objects
M.Ansari, [0911.5312] (cond.mat/statistical Mechanics)

On: an analytical solution to the statistics of hard elongated objects (e.g. needles, rectangles, ellipses, etc)

Elasticity theory describes how a system under distortion is mechanically deformed. There are two approaches to quantitatively study this. The traditional approach is
to analyze the dislocation of fluid rigid boundaries. Depending on the properties of fluid (e.g. viscosity, compressibility, etc.) a variety of different cases appears.

The other approach, which is of our interest, replaces fluid with discrete objects and studies the short-range interaction between these objects. If the objects are spherically-symmetric, their alignments lead to translational ordered/disordered phases.

Frenkel et.al. in a series of papers developed a method that enables to analyze the stress and elasticity of hard spherically-symmetric objects.

A natural generalization is to replace the spherically-symmetric objects with elongated objects. These objects carry a coupling between their translational and rotational degrees of freedom and display orientational ordered/disordered phases; similar to liquid crystals.

Recently, in a series of papers a formalism for direct calculation of elastic properties of hard non-spherically symmetric objects was proposed by Murat, Kantor, and Farago. They considered hard stiffness for these objects in order to prevent the influence of orientational degrees of freedom into kinetic energy. Their method was
developed on the basis of different types of central and non-central short-range interactions; central potential depends only on the relative distance between particles, whereas noncentral potential depends on individual object orientations.

This formalism has been so far applied in different problems such as the wrapping of proteins in DNA, the ordering of complex liquids systems and percolation transitions, and the jamming transitions.

However, this formalism is hard to be solved analytically and a Monte-Carlo simulation should been used to extract its physical properties. Kantor and Kardar in
proposed a self-consistency check for this formalism in one dimension, where instead of non-spherically symmetric objects, needles are applied. The center of needles
are on a line and the angle of each needle orientation is randomly chosen. They solved this model by transfer matrix method numerically and reported an agreement
between the numerical and MC results.

The purpose of my recent publication is to reconsider elongated objects in one dimension and propose an analytical solution that, in our opinion, goes a step forward since it allows to obtain analytical formulation for some collective properties obtained so far only numerically.

To this end, we eliminate the dependence of free energy on the absolute value of an angle, thus make the orientation completely isotropic.

Interparticle distance and elasticity coefficients are derived into analytical formulations and verify the exact model results of Kardar and Kantor. We generalize our formalism to cover different types of elongated objects and repeat to derive them and verify recent results. This formalism allows to evaluate other properties of the same class, such as inverse distance between needles.

We verify the inverse distance law of sound pressure in high densities. As expected from a previous study on spherically-symmetric object, in needles model the expectation value of inverse distance below a critical pressure does not scale as the inverse of distance.

Energy released by Volcano and earthquake

The energy released from a Volcano is 10^13 Joules. The chemical bond energy between carbon molecules to form 12 grams of carbon compound is typically 10^5 Joules. With the 10^13 Joules one can vaporize 10^3 Tonnes of Carbon.

In the case of an earthquake of magnitude 6, about 10^15 Joules of energy is released, some of these are released before the main shock. This amount is necessary to vaporize 10^5 Tonnes of carbon. Although most of the energy is released in the thermal form, but anyhow should it be unrealistic that one studies the formation of an earthquake cloud before an earthquake on top of the region gaining this energy.

P.S.> The above picture is taken from here.

Reports on NPB findings from M.H. Ansari and co-researchers provide new insights

Source: VerticalNews Physics

May 5th, 2008

"Without imposing the trapping boundary conditions and only from within the very definition of area it is shown that the loop quantization of area manifests an unexpected degeneracy in area eigenvalues," researchers in Waterloo, Canada report.
"This could lead to a deeper understanding of the microscopic description of a quantum black hole," wrote M.H. Ansari and colleagues.

The researchers concluded: "If a certain number of semi-classically expected properties of black holes are imposed on a quantum surface its entropy coincides with the Bekenstein-Hawking entropy."

Ansari and colleagues published their study in NPB...