نتایج جستجو برای: qubit

تعداد نتایج: 11810  

Journal: :Physical review 2021

Scaling up spin qubit systems requires high-fidelity single-qubit and two-qubit gates. Gate fidelities exceeding $98\%$ were already demonstrated in silicon based single double quantum dots, whereas for the realization of larger arrays crosstalk effects on neighboring qubits must be taken into account. We analyze impacted by when performing operations neighbor with a simple Heisenberg model. Fu...

Journal: :Physical review letters 2012
Daniel Sank R Barends Radoslaw C Bialczak Yu Chen J Kelly M Lenander E Lucero Matteo Mariantoni A Megrant M Neeley P J J O'Malley A Vainsencher H Wang J Wenner T C White T Yamamoto Yi Yin A N Cleland John M Martinis

We measure the dependence of qubit phase coherence and flux noise on inductor loop geometry. While wider inductor traces change neither the flux noise power spectrum nor the qubit dephasing time, increased inductance leads to a simultaneous increase in both. Using our new tomographic protocol for measuring low frequency flux noise, we make a direct comparison between the flux noise spectrum and...

Journal: :Physical review letters 2004
A Nazir B W Lovett S D Barrett T P Spiller G A D Briggs

We present a novel scheme for performing a conditional phase gate between two spin qubits in adjacent semiconductor quantum dots through delocalized single exciton states, formed through the interdot Förster interaction. We consider two resonant quantum dots, each containing a single excess conduction band electron whose spin embodies the qubit. We demonstrate that both the two-qubit gate and a...

Journal: :Quantum Information & Computation 2013
Charles D. Hill Austin G. Fowler David S. Wang Lloyd Christopher L. Hollenberg

In this paper we demonstrate how data encoded in a five-qubit quantum error correction code can be converted, fault-tolerantly, into a seven-qubit Steane code. This is achieved by progressing through a series of codes, each of which fault-tolerantly corrects at least one error. Throughout the conversion the encoded qubit remains protected. We found, through computational search, that the method...

Journal: :Physical review letters 2012
D Ristè J G van Leeuwen H-S Ku K W Lehnert L DiCarlo

We demonstrate initialization by joint measurement of two transmon qubits in 3D circuit quantum electrodynamics. Homodyne detection of cavity transmission is enhanced by Josephson parametric amplification to discriminate the two-qubit ground state from single-qubit excitations nondestructively and with 98.1% fidelity. Measurement and postselection of a steady-state mixture with 4.7% residual ex...

Journal: :Nano letters 2010
Junho Suh Matthew D LaHaye Pierre M Echternach Keith C Schwab Michael L Roukes

We demonstrate the parametric amplification and noise squeezing of nanomechanical motion utilizing dispersive coupling to a Cooper-pair box qubit. By modulating the qubit bias and resulting mechanical resonance shift, we achieve gain of 30 dB and noise squeezing of 4 dB. This qubit-mediated effect is 3000 times more effective than that resulting from the weak nonlinearity of capacitance to a ne...

2009
Chih-Sung Chuu Chuanwei Zhang

We study the suppression of noise-induced phase decoherence in a single atomic qubit by employing pulse sequences. The atomic qubit is composed of a single neutral atom in a far-detuned optical dipole trap and the phase decoherence may originate from the laser intensity and beam pointing fluctuations, as well as magnetic field fluctuations. We show that suitable pulse sequences may prolong the ...

2003
Stephen A. Fenner

We show that, for even n, evolving n qubits according to a simple Hamiltonian can be used to exactly implement an (n + 1)-qubit parity gate, which is equivalent in constant depth to an (n + 1)-qubit fanout gate. We also observe that evolving the Hamiltonian for three qubits results in an inversion-on-three-way-equality gate, which together with single-qubit operations is universal for quantum c...

Journal: :New Journal of Physics 2022

Quantum and biological systems are seldom discussed together as they seemingly demand opposing conditions. Life is complex, "hot wet" whereas quantum objects small, cold well controlled. Here, we overcome this barrier with a tardigrade -- microscopic multicellular organism known to tolerate extreme physiochemical conditions via latent state of life cryptobiosis. We observe coupling between the ...

2012
Georg M. Reuther Peter Hänggi Sigmund Kohler

We study qubit decoherence under generalized dispersive readout, i.e., we investigate a qubit coupled to a resonantly driven dissipative harmonic oscillator. We provide a complete picture by allowing for arbitrarily large qubit-oscillator detuning and by considering also a coupling to the square of the oscillator coordinate, which is relevant for flux qubits. Analytical results for the decohere...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید