PROGRAM

QuTech Seminar Series - Quantum dynamics and control of spins and qubits

Date:

Time:

Mondays: 16:00-17:00 hrs, Wednesdays: 14:00-15:00 hrs

Location:

Delft, building 22, Lorentzweg 1, room G (F207)

 

QuTech PI Viatcheslav Dobrovitski will host a seminar series "Quantum dynamics and control of spins and qubits". The primary expected audience is PhD students and postdocs, but everyone interested is welcome to attend. The plan is to have one lecture per week, with an occasional second seminar devoted to more advanced topics, for those who are interested in deeper or broader coverage of the subject.

This seminar series has two goals. One is to help students and postdocs learn in depth the basics of the dynamics and control of spins in solids. The other goal is to broaden the standard coverage, by elucidating the themes common for other types of qubits, and establishing connections with the relevant ideas from other areas of physics (quantum optics, nanomagnetism, nuclear/electronic magnetic resonance, etc.) Currently, the corresponding material is spread over various textbooks and research papers; this seminar will combine different pieces together, and develop a unifying picture for spin dynamics and control in different regimes, based on few general underlying ideas.

See below for the syllabus and the schedule. There is no need to register for the seminars. For any additional info, please contact: V.V.Dobrovitski@tudelft.nl

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V. V. Dobrovitski.
"Quantum dynamics and control of spins and qubits".
Tentative syllabus - Version 2.1

1) Spin. Quantization axis - correct choice, and why it matters. Rotating frame, secular approximation. Rabi oscillations, weak vs. strong driving.

Extra: non-secular terms, Bloch-Siegert shift, fractional frequency resonances. Quantum optical rotating-wave approximation, small coupling regime in quantum optics, optical Rabi oscillations.

2) Spin-spin interactions. Exchange interactions. Dipole-dipole coupling. Like and unlike spins, secular Hamiltonians. Singularities of dipolar coupling, micromagnetic/shape effects. Rare spins, singularities of dipolar coupling in this case.

Extra: method of moments, dipolar coupling in rigid lattice

3) Spin-spin interactions as noise. Noise models: delta-correlated noise, Ornstein-Uhlenbeck process. Markovian noise - two definitions, their differences.

Extra: Bloch-Redfield theory (spins and quantum optics), quantum noise (spins and quantum optics).

4) Free induction decay, spin echo, dynamical decoupling (DD). Different DD protocols, relations to the group theory (briefly). Magnus expansion. Floquet theorem, Floquet dynamics. Cumulant expansion for noise models.

Extra: long-time dynamics of DD protocols.

5) Few-spin dynamics. Electron-nuclear systems, partial secular approximation. ESEEM. Time-dependent quantization axis. ESEEM for the system of non-interacting spins. Connection between ESEEM and noise model (small coupling, large-N limit).

6) Spin-phonon coupling: mechanisms (electronic and nuclear spins). Spin-phonon relaxation: direct processes, 2-phonon processes, Orbach processes, quasi-static quasi-relaxation (analogy with ESEEM) and longitudinal dephasing. Field and temperature dependence. Phonon bottleneck.

7) Few-spin dynamics; like and unlike spins. Spin diffusion, role of disorder, localization (briefly). Multiple quantum coherences: creation, control, measurement, applications. Few-spin DD. Dipolar couplings, WHH and MREV sequences.

Extra: NMR, typical nuclei (C and H), chemical shift, typical systems and couplings. Decoupling by strong driving: static bath and Ornstein-Uhlenbeck process. Proton-driven spin diffusion. Magic angle spinning. MAS-driven spin diffusion.

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Schedule: All session will take place in Delft, building 22, Lorentzweg 1, room G (F207)

Seminar Series Slava Dobrovitski QuTech

Room G is confirmed at 16.00-17.00 on:
1) Monday 4 September
2) Monday 11 September    
3) Monday 18 September
4) Monday  25 September
5) Monday 2 October          
6) Monday 9 October
7) Monday 16 October

Second Seminar Series Slava Dobrovitski QuTech
Room G is also confirmed at 14.00-15.00:
1) Wednesday 13 October
2) Monday 18 October
3) Wednesday 20 October
4) Wednesday 27 October
5) Wednesday 18 October

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