This
topical group, extending over two weeks, will bring together a select
number of practitioners in the field of Quantum Information Science,
Adiabatic Quantum Computing, as well as the interface between Atomic
Physics, Quantum Optics, and Condensed Matter Physics. The dates are
Oct. 617. There will be a small number of talks (12) a day and ample
time for discussions and interactions.
Schedule:
Mon. Oct. 6 
10:00am  2:00pm, Pratt Conference Room, CfA
2:00pm  6:00pm, LISE 303, Harvard Physics

Tues. Oct. 7 
10:00 am  LISE 319
Xuedong Hu  Univ. of Buffalo and RIKEN
Semiconducting Qubits
2:00 pm  LISE 303
Edward Laird  Harvard
"Hyperfinemediated gatedriven electron spin resonance"
Other rooms reserved for informal meeting:
10:00 am  12:00 am, Lyman 330, Harvard Physics and 11:30am  3:00pm, Tea Room, CfA

Wed. Oct 8 
10:00 am  Tearoom  Center for Astrophysics
Sahel Ashhab, Digital Materials Laboratory RIKEN
"Quantum nonlocality of a single delocalized particle"
2:00pm  LISE 303, Harvard Physics
Hendrik Bluhm (Harvard) Title TBD
Joint Atomic Physics Colloquium
4:30 pm  Dave Cory (MIT), "Error Finding and Control for Quantum Processors"
Jefferson Lab 356
Other rooms reserved for informal meeting:
10:00am  12:30pm, Phillips Auditorium, CfA
Other rooms reserved: 10:3012:30 Phillips

Thurs. Oct 9 
10:00 am  1:00pm Meeting Room C34
Dr. William D. Oliver, MIT Lincoln Laboratory, Analog Device Technology Group
"Amplitude spectroscopy of a superconducting artificial atom"
Dr. Jonas Bylander, MIT Research Laboratory of Electronics, Superconducting Circuits and Quantum Computation Group, MIT
"
Pulse calibration and nonadiabatic control of a superconducting artificial atom"
2:00 pm  LISE 303, Harvard Physics
Jimmy Williams (Harvard)
"The Effect of pn Junctions on Mesoscale Transport in Graphene"
3:00 pm
Jeff Miller (Harvard)
“Quasiparticle Properties from Tunneling in the nu = 5/2 Fractional Quantum Hall State”

Fri. Oct 10 
The
Harvard University Center for Nanoscale Systems (CNS) and the National
Nanotechnology Infrastructure Network announce (NNIN) a one day
workshop: Photosynthesis – from Elementary Processes to Quantum
SimulationDivision Room  M102 in Mallinckrodt, 12 Oxford Street from
9am4pm
For
More Information Regarding this one day workshop, please contact, Anna
B Shin, Group Administrator, Department of Chemistry and Chemical
Biology, 6174969964. or online at http://cns.fas.harvard.edu/about/docs/photosynthesis.pdf
Other rooms reserved: 10:302:00 Pratt

Mon. Oct 13 
10 am: Dr. Sekhar Ramanathan, MIT Title: NMR studies of quantum information processes
4:30 pm: Frank Gaitan, RIKEN and Univ. of S. Illinois: Density functional theory and quantum computation
Abstract:
We demonstrate the applicability of groundstate and timedependent
density functional theory to quantum computing by proving the
HohenbergKohn and RungeGross theorems for a fermion system
representing N qubits. Timedependent density functional theory is used
to determine the minimum energy gap Delta(N) arising from application
of the quantum adiabatic evolution algorithm to the NPComplete problem
MAXCUT. As density functional theory has been used to treat quantum
systems with as many as 650 interacting degrees of freedom, this raises
the realistic prospect of evaluating the gap Delta(N) for systems with
N ~ 650 qubits.
Ref. F. Gaitan and F. Nori, Density functional theory and quantum computation, arXiv:0809.1170v1 [quantph]

Tues. Oct 14 
10:00am  11:00am, Pratt, CfA
"Quantum control of spins in diamond"
Paola Cappellaro, ITAMP
NitrogenVacancy
(NV) centers in diamond have emerged as excellent candidates for
quantum information processing, since they can be optically polarized
and detected, and present good coherence properties even at room
temperature. In this talk I will present the application of coherent
control techniques to the electronic and nuclear spins associated with
NV centers. I will first show how this solid state system can be
used as the building block of a scalable architecture for quantum
computation or communication, and present potential strategies for the
efficient control of these small quantum registers.
Then I will present a novel approach to magnetometry, based on NV
centers, that takes advantage of coherent control techniques and the
confinement of the sensing spins into a sample of nanometer dimensions.
The resulting magnetic sensor is projected to yield an unprecedented
combination of high sensitivity and spatial resolution, with the
potential of exciting applications in bioscience, materials science,
and single electronic and nuclear spin detection.
11:00 am  12:00 noon, Pratt CfA
Jero Maze, "Nanoscale magnetic sensing using a single electron spin in
diamond"
3:00 pm Tearoom, CfA: Dr. Toshiaki Iitaka, RIKEN: Title: Largescale simulation of timeevolving qubits
Natural timeevolution of qubits is one of attractive approaches for quantum information [1]. I will talk about numerical techniques for simulating the timeevolution of interacting spins [2] and their application to quantum magnets [3] and quantum dots [4].
[1] K. Maruyama, T. Iitaka, F. Nori, Enhancement of entanglement transfer in a spin chain by phaseshift control Phys. Rev. A 75, 012325 (2007). [2] T. Iitaka, T. Ebisuzaki, Algorithm for linear response functions at finite temperatures, Application to ESR spectrum of s=1/2 antiferromagnet Cu benzoate. Phys. Rev. Lett. 90, 047203 (2003). [3] M. Machida, T. Iitaka and S. Miyashita, Temperature dependence of ESR intensity for the nanoscale molecular magnet V15, J. Phys. Soc. Jpn. Suppl. 74, 107110 (2005). [4] Shintaro Nomura and Toshiaki Iitaka, Linear scaling calculation of a ntype GaAs quantum dot, Phys. Rev. E 76, 037701 (2007).

Wed. Oct 15 
10:00 am LISE 3rd floor Room 320
Speaker: Robert Johansson: Singleartificialatom lasing and its suppression by strong pumping
Abstract:
We consider a system composed of a single artificial atom coupled to a
cavity mode. The artificial atom is biased such that the most dominant
relaxation process in the system takes the atom from its ground state
to its excited state, thus ensuring population inversion. Even under
this condition, lasing action can be suppressed if the `relaxation'
rate, i.e. the pumping rate, is larger than a certain threshold value.
Using simple transitionrate arguments and a semiclassical calculation,
we derive analytic expressions for the lasing suppression condition and
the state of the cavity in both the lasing and suppressedlasing
regimes. The results of numerical calculations agree very well with the
analytically derived results. Our analysis and results are relevant to
the recently realized superconducting artificialatom laser
Reference:
S. Ashhab, J.R. Johansson, A.M. Zagoskin, F. Nori
Singleartificialatom lasing and its suppression by strong pumping
(2008).
4:30 Jefferson Lab 356 Special ITAMP Colloquium
Speaker: Franco Nori: Designing superconducting qubit circuits that exhibit atomicphysicslike phenomena on a chip
Abstract: Superconducting (SC) circuits can behave like atoms making
transitions between a few energy levels. Such circuits can test quantum
mechanics at macroscopic scales and be used to conduct atomicphysics
experiments on a silicon chip. This talk overviews a few of our
theoretical studies on SC circuits and quantum information processing
(QIP) including: SC qubits for single photon generation and for lasing;
controllable couplings among qubits; how to increase the coherence time
of qubits using a capacitor in parallel to one of the qubit junctions;
hybrid circuits involving both charge and flux qubits; quantum
tomography in SC circuits; preparation of macroscopic quantum
superposition states of a cavity field via coupling to a SC qubit;
generation of nonclassical photon states using a SC qubit in a
microcavity; scalable qubit circuits; and information processing with
SC qubits in a microwave field. Controllable couplings between qubits
can be achieved either directly or indirectly. This can be done either
with or without coupler circuits, as well as either with or without
databuses like EM fields in cavities (e.g., we will describe both the
variablefrequency magnetic flux approach and also a generalized
doubleresonance approach that we introduced). It is also possible to
"turn a quantum bug into a feature'' by using microscopic defects as
qubits, and the macroscopic junction as a controller of it. We have
also studied ways to implement "cluster states'' in SC circuits.
For a general overview of this field, see, J.Q. You and F. Nori, Physics Today 58, No. 11, 42 (2005)

Thurs. Oct 16 
10:00am  2:00pm, Jefferson 453, Harvard Physics
10:00 Alexey Akimov, "Quantum optics with nanoscale surface plasmons"
11:00 Frank Koppens, "NearField Electrical Detection of Guided Surface Plasmons"
12:00 Liang Jiang, "Anyonic interferometry and protected memories in
atomic spin lattices"
2:00pm  5:00pm, Classroom, CfA

Fri. Oct 17 
12:00pm , Lyman 425
Toshi Iitaka, "Quantum Dynamics"
1:00 pm, Lyman 425
Frank Gaitan, "Quantum Computing and Density Functional Theory"

