English
Related papers

Related papers: Robust Single-Shot Spin Measurement with 99.5% Fid…

200 papers

High fidelity qubit readout is critical in order to obtain the thresholds needed to implement quantum error correction protocols and achieve fault-tolerant quantum computing. Large-scale silicon qubit devices will have densely-packed arrays…

Using the recently reported mode locking effect we demonstrate a highly robust control of electron spin coherence in an ensemble of (In,Ga)As quantum dots during the single spin coherence time. The spin precession in a transverse magnetic…

We experimentally implement a machine-learning method for accurately identifying unknown pure quantum states. The method, called single-shot measurement learning, achieves the theoretical optimal accuracy for $\epsilon = O(N^{-1})$ in state…

Quantum Physics · Physics 2021-05-05 Sang Min Lee , Hee Su Park , Jinhyoung Lee , Jaewan Kim , Jeongho Bang

The knowledge of the energy spectrum completely defines the dynamics of a quantum system for a given initial state. This makes spectroscopy a key characterization technique when studying or designing qubits and complex quantum systems. In…

Double quantum dots are one of the promising two-state quantum systems for realizing qubits. In the quest of successfully manipulating and reading information in qubit systems, it is of prime interest to control the charge response of the…

Mesoscale and Nanoscale Physics · Physics 2022-10-04 A. Crépieux , M. Lavagna

In recent advancements of quantum computing utilizing spin qubits, it has been demonstrated that this platform possesses the potential for implementing two-qubit gates with fidelities exceeding 99.5%. However, as with other qubit platforms,…

Quantum Physics · Physics 2024-03-20 Irina Heinz , Adam R. Mills , Jason R. Petta , Guido Burkard

Transport measurements are presented on a class of electrostatically defined lateral dots within a high mobility two dimensional electron gas (2DEG). The new design allows Coulomb Blockade(CB) measurements to be performed on a single…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 M. Ciorga , A. S. Sachrajda , P. Hawrylak , C. Gould , P. Zawadzki , S. Jullian , Y. Feng , Z. Wasilewski

We study numerically the process of nuclear spin measurement in a solid-state quantum computer of the type proposed by Kane by modeling the quantum dynamics of two coupled nuclear spins on $^{31}$P donors implanted in silicon. We estimate…

Condensed Matter · Physics 2007-05-23 Gennady P. Berman , David K. Campbell , Gary D. Doolen , Kirill E. Nagaev

We consider evolution of a double quantum dot (DQD) two-electron spin qubit which is continuously weakly measured with a linear charge detector (quantum point contact). Since the interaction between the spins of two electrons depends on…

Mesoscale and Nanoscale Physics · Physics 2009-06-12 Rusko Ruskov , Viatcheslav V. Dobrovitski , Bruce N. Harmon

We investigate the dynamics of electron spin qubits in quantum dots. Measurement of the qubit state is realized by a charge current through the dot. The dynamics is described in the framework of the quantum trajectory approach, widely used…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Holger Schaefers , Walter T. Strunz

The double quantum dot device benefits from the advantages of both the spin and charge qubits, while offering ways to mitigate their drawbacks. Careful gate voltage modulation can grant greater spinlike or chargelike dynamics to the device,…

Mesoscale and Nanoscale Physics · Physics 2022-08-12 Vincent Reiher , Yves Bérubé-Lauzière

We propose a spin-selective coherent electron transfer in a silicon-quantum-dot array. Oscillating magnetic fields and temporally controlled gate voltages are utilised to separate the electron wave function into different quantum dots…

Mesoscale and Nanoscale Physics · Physics 2018-01-24 Shumpei Masuda , Kuan Yen Tan , Mikio Nakahara

Among the surprising features of quantum measurements, the problem of distinguishing and antidistinguishing general quantum measurements is fundamentally appealing. Unlike classical systems, quantum theory offers entangled states and…

Quantum Physics · Physics 2025-08-19 Satyaki Manna , Sneha Suresh , Manan Singh Kachhawaha , Debashis Saha

The measurement of single quanta in a collection of coherently interacting objects is transformative in the investigations of emergent quantum phenomena. An isolated nuclear-spin ensemble is a remarkable platform owing to its coherence, but…

We measure telegraph noise of current fluctuations in an electrostatically defined quantum dot in bilayer graphene by real-time detection of single electron tunneling with a capacitively coupled neighboring quantum dot. Suppression of the…

The feasibility of high-fidelity single-qubit operations of a hole spin in a quantum dot molecule by electric g tensor control is demonstrated. Apart from a constant external magnetic field the proposed scheme allows for an exclusively…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 Robert Roloff , Thomas Eissfeller , Peter Vogl , Walter Pötz

Results of calculations and high source-drain transport measurements are presented which demonstrate voltage-tunable entanglement of electron pairs in lateral quantum dots. At a fixed magnetic field, the application of a judiciously-chosen…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Jordan Kyriakidis , M. Pioro-Ladriere , M. Ciorga , A. S. Sachrajda , P. Hawrylak

We demonstrate coherent optical control of a single hole spin confined to an InAs/GaAs quantum dot. A superposition of hole spin states is created by fast (10-100 ps) dissociation of a spin-polarized electron-hole pair. Full control of the…

Mesoscale and Nanoscale Physics · Physics 2012-01-09 T. M. Godden , J. H. Quilter , A. J. Ramsay , Yanwen Wu , P. Brereton , S. J. Boyle , I. J. Luxmoore , J. Puebla-Nunez , A. M. Fox , M. S. Skolnick

We outline a scheme to accomplish measurements of a solid state double well system (DWS) with both one and two electrons in non-localised bases. We show that, for a single particle, measuring the local charge distribution at the midpoint of…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 T. M. Stace , S. D. Barrett , H. -S. Goan , G. J. Milburn

Assuming a well-behaving quantum-to-classical transition, measuring large quantum systems should be highly informative with low measurement-induced disturbance, while the coupling between system and measurement apparatus is "fairly simple"…

Quantum Physics · Physics 2017-07-19 Tomer Jack Barnea , Marc-Olivier Renou , Florian Fröwis , Nicolas Gisin