ELFT HÍRADÓ

[Andras Palyi <andraspalyi AT caesar.elte.hu>]

Az ELTE Nanofizika Szeminarium jovo hetfoi eloadasa:


Dimitrie Culcer (University of New South Wales, Sydney, Ausztralia):
Dephasing of single-spin qubits due to charge noise and spin-orbit coupling

Idopont: 2015. junius 8. hetfo, 10:15
Helyszin: ELTE Eszaki Tomb, 5.128-as terem (1117 Budapest, Pazmany Peter 
setany 1/A)

Kivonat:
“Quantum dot quantum computing architectures rely on systems in which 
inversion symmetry is broken, and spin-orbit coupling is present, causing 
even single-spin qubits to be susceptible to charge noise. I will discuss an 
effective Hamiltonian for the combined action of noise and spin-orbit 
coupling on a single-spin qubit, identify the mechanisms behind dephasing, 
and estimate the free induction decay dephasing times T2* for common 
materials such as Si and GaAs. Dephasing is driven by noise matrix elements 
that cause relative fluctuations between orbital levels, which are dominated 
by screened whole charge defects and unscreened dipole defects in the 
substrate. Dephasing times T2* differ markedly between materials, and can be 
enhanced by increasing gate fields, choosing materials with weak spin-orbit, 
making dots narrower, or using accumulation dots. I will also discuss 
implications for qubits using micromagnets. "


Minden erdeklodot szivesen latunk.

Udvozlettel,
Palyi Andras