Electrical control of a solid-state flying qubit

Yamamoto, Mahito; Takada, Shintaro; Bäuerle, Christopher; Watanabe, Kenta; Wieck, A. D.; Tarucha, Seigo

doi:10.1038/nnano.2012.28

Cited by 125 publications

(152 citation statements)

References 29 publications

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“…Of course, in standard quantum Hall setups the different transport behavior of the spatially separated edge states has been discussed, for instance in strongly differing localization 17 or in switchable quantum dots coupled to single edge states 18 . Various quantum interferometer devices and quantum gates based on edges states have been realized 19,20 . We put forward two effects which to our knowledge have not yet been studied: (i) the Fermi velocity can be made extremely direction-sensitive, i.e., it can differ from one edge to the other by orders of magnitude.…”

Section: Introductionmentioning

confidence: 99%

Tunable and direction-dependent group velocities in topologically protected edge states

Uhrig

2016

Phys. Rev. B

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Topological effects continue to fascinate physicists since more than three decades. One of their main applications are high-precision measurements of the resistivity. We propose to make also use of the spatially separated edge states. It is possible to realize strongly direction-dependent group velocities. They can also be tuned over orders of magnitude so that robust and tunable delay lines and interference devices are within reach.

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Section: Introductionmentioning

confidence: 99%

Tunable and direction-dependent group velocities in topologically protected edge states

Uhrig

2016

Phys. Rev. B

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“…In an electronic analogue, the decomposition of electron pairs represents an essential building block for using the quantum state of ballistic electrons in electron quantum optics [4][5][6][7] . The scattering of electrons has been used to probe the particle statistics of stochastic sources in Hanbury Brown and Twiss experiments 8,9 and the recent advent of on-demand sources further offers the possibility to achieve indistinguishability between multiple sources in Hong-Ou-Mandel experiments [10][11][12][13][14][15] .…”

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confidence: 99%

Partitioning of on-demand electron pairs

et al. 2014

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The on-demand generation and separation of entangled photon pairs are key components of quantum information processing in quantum optics [1][2][3] . In an electronic analogue, the decomposition of electron pairs represents an essential building block for using the quantum state of ballistic electrons in electron quantum optics [4][5][6][7] . The scattering of electrons has been used to probe the particle statistics of stochastic sources in Hanbury Brown and Twiss experiments 8,9 and the recent advent of on-demand sources further offers the possibility to achieve indistinguishability between multiple sources in Hong-Ou-Mandel experiments [10][11][12][13][14][15] . Cooper pairs impinging stochastically at a mesoscopic beamsplitter have been successfully partitioned, as verified by measuring the coincidence of arrival [16][17][18][19][20][21] . Here, we demonstrate the splitting of electron pairs generated on demand. Coincidence correlation measurements allow the reconstruction of the full counting statistics, revealing regimes of statistically independent, distinguishable or correlated partitioning, and have been envisioned as a source of information on the quantum state of the electron pair [22][23][24][25][26] . The high pair-splitting fidelity opens a path to future on-demand generation of spin-entangled electron pairs from a suitably prepared two-electron quantum-dot ground state.The few-electron source is based on a single-parameter non-adiabatic quantized charge pump [27][28][29] , which enables the deterministic generation of single electrons and electron pairs with tunable emission energy 12,30 . Non-equilibrium electrons propagate along the edge of a quantum Hall sample with minimal inelastic scattering. The device and measurement set-up are presented in Fig. 1. An energy-selective detector barrier splits the incoming beam of electrons into two detector paths. The coincidence of arrival of electrons in the two detector channels leads to positive correlation between the time-dependent current signals. These correlations are inferred from a measurement of the zero-frequency cross-correlation shot noise. Although an oscillator-controlled electron source is noiseless 31 , the splitting of electron pairs generates partitioning noise and enables tomography of the probability distribution for the partitioning outcomes within each emission cycle.The generation and energy-selective detection of on-demand non-equilibrium electrons was demonstrated with the electron source configured to emit one electron with charge e and repetition frequency f of 280 MHz. Figure 2 shows the transmitted current I T as a function of barrier energy. The maximum level of I T is 2% below the emission current I P = 1 ef due to residual inelastic scattering events on the 2-µm-long path to the barrier (the emission error of the source is <1 × 10 −4). For energies greater than 57 meV, the current is pinched off as all of the emitted electrons are reflected at the beamsplitter. The emission energy is defined by the exit barrier height and ca...

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“…A few works propose setups for 'flying qubits' [1][2][3][4][5][6] that encode the quantum information into the paths taken by the electrons. Those systems could be realized in Mach-Zehnder interferometers in the quantum Hall regime [7][8][9] or Aharonov-Bohm geometries 10 . Before designing any of those circuits, however, a necessary step is the understanding of the basic, potentially new, physics associated with the time-resolved dynamics in delocalized nanoelectronic systems.…”

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confidence: 99%

Dynamical control of interference using voltage pulses in the quantum regime

Gaury¹,

Waintal²

2014

Nat Commun

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As a general trend, nanoelectronics experiments are shifting towards frequencies so high that they become comparable to the device's internal characteristic time scales, resulting in new opportunities for studying the dynamical aspects of quantum mechanics. Here we theoretically study how a voltage pulse (in the quantum regime) propagates through an electronic interferometer (Fabry-Perot or Mach-Zehnder). We show that extremely fast pulses provide a conceptually new tool for manipulating quantum information: the possibility to dynamically engineer the interference pattern of a quantum system. Striking physical signatures are associated with this new regime: restoration of the interference in presence of large bias voltages; negative currents with respect to the direction of propagation of the voltage pulse; and oscillation of the total transmitted charge with the total number of injected electrons. The present findings have been made possible by the recent unlocking of our capability for simulating time-resolved quantum nanoelectronics of large systems.

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Electrical control of a solid-state flying qubit

Cited by 125 publications

References 29 publications

Tunable and direction-dependent group velocities in topologically protected edge states

Tunable and direction-dependent group velocities in topologically protected edge states

Partitioning of on-demand electron pairs

Dynamical control of interference using voltage pulses in the quantum regime

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