scholarly journals Charge noise suppression in capacitively coupled singlet-triplet spin qubits under magnetic field

2021 ◽  
Vol 103 (16) ◽  
Author(s):  
Guo Xuan Chan ◽  
J. P. Kestner ◽  
Xin Wang
2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Xin Wang ◽  
Edwin Barnes ◽  
S Das Sarma

AbstractCapacitively coupled semiconductor spin qubits hold promise as the building blocks of a scalable quantum computing architecture with long-range coupling between distant qubits. However, the two-qubit gate fidelities achieved in experiments to date have been severely limited by decoherence originating from charge noise and hyperfine interactions with nuclear spins, and are currently unacceptably low for any conceivable multi-qubit gate operations. Here, we present control protocols that implement two-qubit entangling gates while substantially suppressing errors due to both types of noise. These protocols are obtained by making simple modifications to control sequences already used in the laboratory and should thus be easy enough for immediate experimental realisation. Together with existing control protocols for robust single-qubit gates, our results constitute an important step toward scalable quantum computation using spin qubits in semiconductor platforms.


2021 ◽  
Vol 28 (12) ◽  
pp. 123505
Author(s):  
Shali Yang ◽  
Tianxiang Zhang ◽  
Hanlei Lin ◽  
Hao Wu ◽  
Qiang Zhang

2018 ◽  
Vol 16 (6) ◽  
pp. 385-390
Author(s):  
Shikha BINWAL ◽  
Jay K JOSHI ◽  
Shantanu Kumar KARKARI ◽  
Predhiman Krishan KAW ◽  
Lekha NAIR ◽  
...  

A floating emissive probe has been used to obtain the spatial electron temperature (Te) profile in a 13.56 MHz parallel plate capacitive coupled plasma. The effect of an external transverse magnetic field and pressure on the electron temperature profile has been discussed. In the un-magnetised case, the bulk region of the plasma has a uniform Te. Upon application of the magnetic field, the Te profile becomes non-uniform and skewed.  With increase in pressure, there is an overall reduction in electron temperature. The regions adjacent to the electrodes witnessed a higher temperature than the bulk for both cases. The emissive probe results have also been compared with particle-in-cell simulation results for the un-magnetised case.


2020 ◽  
Vol 101 (19) ◽  
Author(s):  
Jorge Cayao ◽  
Mónica Benito ◽  
Guido Burkard

2016 ◽  
Vol 116 (11) ◽  
Author(s):  
Frederico Martins ◽  
Filip K. Malinowski ◽  
Peter D. Nissen ◽  
Edwin Barnes ◽  
Saeed Fallahi ◽  
...  

2014 ◽  
Vol 105 (19) ◽  
pp. 192102 ◽  
Author(s):  
Adam Bermeister ◽  
Daniel Keith ◽  
Dimitrie Culcer

2021 ◽  
Author(s):  
Sayan Kahali ◽  
Satya V.V.N. Kothapalli ◽  
Xiaojian Xu ◽  
Ulugbek S Kamilov ◽  
Dmitriy A Yablonskiy

Purpose: To introduce a Deep-Learning-Based Accelerated and Noise-Suppressed Estimation (DANSE) method for reconstructing quantitative maps of biological tissue cellular-specific, and hemodynamic-specific, from Gradient-Recalled-Echo (GRE) MRI data with multiple gradient-recalled echoes. Methods: DANSE method adapts supervised learning paradigm to train a convolutional neural network for robust estimation of and maps free from the adverse effects of macroscopic (B0) magnetic field inhomogeneities directly from the GRE magnitude images without utilizing phase images. The corresponding ground-truth maps were generated by means of a voxel-by-voxel fitting of a previously-developed biophysical quantitative GRE (qGRE) model accounting for tissue, hemodynamic and -inhomogeneities contributions to GRE signal with multiple gradient echoes using nonlinear least square (NLLS) algorithm. Results: We show that the DANSE model efficiently estimates the aforementioned brain maps and preserves all features of NLLS approach with significant improvements including noise-suppression and computation speed (from many hours to seconds). The noise-suppression feature of DANSE is especially prominent for data with SNR characteristic for typical GRE data (SNR~50), where DANSE-generated and maps had three times smaller errors than that of NLLS method. Conclusions: DANSE method enables fast reconstruction of magnetic-field-inhomogeneity-free and noise-suppressed quantitative qGRE brain maps. DANSE method does not require any information about field inhomogeneities during application. It exploits spatial patterns in the qGRE MRI data and previously-gained knowledge from the biophysical model, thus producing clean brain maps even in the environments with high noise levels. These features along with fast computational speed can lead to broad qGRE clinical and research applications.


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