Cavity-enhanced broadband photonic Rabi oscillation

The sequence of the human brain can be configured by the originated strongly coupling fields to a pair of the ionic substances(bio-cells) within the microtubules. From which the dipole oscillation begins and transports by the strong trapped force, which is known as a tweezer. The tweezers are the trapped polaritons, which are the electrical charges with information. They will be collected on the brain surface and transport via the liquid core guide wave, which is the mixture of blood content and water. The oscillation frequency is called the Rabi frequency, is formed by the two-level atom system. Our aim will manipulate the Rabi oscillation by an on-chip device, where the quantum outputs may help to form the realistic human brain function for humanoid robotic applications.

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Robust and fast post-processing of single-shot spin qubit detection events with a neural network

Scientific Reports ◽

10.1038/s41598-021-95562-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Tom Struck ◽

Javed Lindner ◽

Arne Hollmann ◽

Floyd Schauer ◽

Andreas Schmidbauer ◽

...

Keyword(s):

Neural Network ◽

Neural Networks ◽

Bayesian Inference ◽

Rabi Oscillation ◽

Detection Methods ◽

Measured Signal ◽

Single Shot ◽

Post Processing ◽

Readout Signal ◽

Spin Qubit

AbstractEstablishing low-error and fast detection methods for qubit readout is crucial for efficient quantum error correction. Here, we test neural networks to classify a collection of single-shot spin detection events, which are the readout signal of our qubit measurements. This readout signal contains a stochastic peak, for which a Bayesian inference filter including Gaussian noise is theoretically optimal. Hence, we benchmark our neural networks trained by various strategies versus this latter algorithm. Training of the network with 106 experimentally recorded single-shot readout traces does not improve the post-processing performance. A network trained by synthetically generated measurement traces performs similar in terms of the detection error and the post-processing speed compared to the Bayesian inference filter. This neural network turns out to be more robust to fluctuations in the signal offset, length and delay as well as in the signal-to-noise ratio. Notably, we find an increase of 7% in the visibility of the Rabi oscillation when we employ a network trained by synthetic readout traces combined with measured signal noise of our setup. Our contribution thus represents an example of the beneficial role which software and hardware implementation of neural networks may play in scalable spin qubit processor architectures.

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Coherent nonlinear low-frequency Landau–Zener tunneling induced by magnetic control of a spin qubit in a quantum wire

International Journal of Quantum Information ◽

10.1142/s0219749918500491 ◽

2018 ◽

Vol 16 (06) ◽

pp. 1850049

Author(s):

S. E. Mkam Tchouobiap ◽

J. E. Danga ◽

R. M. Keumo Tsiaze ◽

L. C. Fai

Keyword(s):

Quantum Wire ◽

Modulation Frequency ◽

Strong Dependence ◽

Rabi Oscillation ◽

Low Frequency ◽

Dynamical Evolution ◽

Quantum Bit ◽

Confinement Potential ◽

Parabolic Confinement ◽

Parabolic Confinement Potential

This paper presents nonlinear Landau–Zener (LZ) tunneling of an electron spin in an accelerating optical parabolic potential, manifested in a heterostructure quantum wire subjected to a periodic magnetic field comprising a spike and a homogeneous part. In this context, driving the two states of a pure nonlinear two-level quantum bit (qubit) system through an avoided level crossing can result in nontrivial dynamics, especially with and without considering a parabolic confinement potential characterized by a curvature confinement potential. We report two striking nonadiabatic and adiabatic scenarios in low modulation frequency limit which appear when such strength modulation occurs. Firstly, the changes of the amplitude of the driving field without considering a parabolic confinement potential act as a perturbation which mixes the spin states. Here, the dynamical evolution of the tunneling probabilities of the nonadiabatic populations under investigation is analyzed. Secondly, for strong fields and strong dependence of a parabolic confinement potential, the two diabatic states do not cross but present anti-crossing phenomenon as the time tends to infinity, describing an adiabatic transition. However, if the field strength in a wire is weak enough, the level separation of a qubit state switches abruptly around the crossing point, and LZ tunneling applies to the whole dynamical range, from adiabatic to fully nonadiabatic crossing. Locally, the tunneling process can be seen as a two-level system (TLS) undergoing a Rabi oscillation. These results open new prospects for the use of quantum interferences in spin–based devices.

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