The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform

J.-s. Tsai - One of the best experts on this subject based on the ideXlab platform.

  • Coherent control of macroscopic quantum states in a single-Cooper-pair box
    Nature, 1999
    Co-Authors: Y. Nakamura, Yuri A. Pashkin, J.-s. Tsai
    Abstract:

    A nanometre-scale superconducting electrode connected to a reservoir via a Josephson junction constitutes an artificial two-level electronic system: a single-Cooper-pair box. The two levels consist of charge states (differing by 2 e , where e is the electronic charge) that are coupled by tunnelling of Cooper pairs through the junction. Although the two-level system is macroscopic, containing a large number of electrons, the two charge states can be coherently superposed^ 1 , 2 , 3 , 4 . The Cooper-pair box has therefore been suggested^ 5 , 6 , 7 as a candidate for a quantum bit or ‘qubit’—the basic component of a quantum computer. Here we report the observation of quantum oscillations in a single-Cooper-pair box. By applying a Short Voltage Pulse via a gate electrode, we can control the coherent quantum state evolution: the Pulse modifies the energies of the two charge states non-adiabatically, bringing them into resonance. The resulting state—a superposition of the two charge states—is detected by a tunnelling current through a probe junction. Our results demonstrate electrical coherent control of a qubit in a solid-state electronic device.

  • Coherent control of macroscopic quantum states in a single-Cooper-pair box
    Nature, 1999
    Co-Authors: Y. Nakamura, Yuri A. Pashkin, J.-s. Tsai
    Abstract:

    5-7 as a candidate for a quantum bit or 'qubit'—the basic component of a quantum computer. Here we report the observation of quantum oscillations in a single- Cooper-pair box. By applying a Short Voltage Pulse via a gate electrode, we can control the coherent quantum state evolution: the Pulse modifies the energies of the two charge states non- adiabatically, bringing them into resonance. The resulting state— a superposition of the two charge states—is detected by a tunnelling current through a probe junction. Our results demon- strate electrical coherent control of a qubit in a solid-state

  • Coherent control of macroscopic quantum states in a single-Cooper-pair box
    Nature, 1999
    Co-Authors: Y. Nakamura, Yuri A. Pashkin, J.-s. Tsai
    Abstract:

    A small superconducting electrode (a single-Cooper-pair box) connected to a reservoir via a Josephson junction constitutes an artificial two-level system, in which two charge states that differ by 2e are coupled by tunneling of Cooper pairs. Despite its macroscopic nature involving a large number of electrons, the two-level system shows coherent superposition of the two charge states, and has been suggested as a candidate for a qubit, i.e. a basic component of a quantum computer. Here we report on time-domain observation of the coherent quantum-state evolution in the two-level system by applying a Short Voltage Pulse that modifies the energies of the two levels nonadiabatically to control the coherent evolution. The resulting state was probed by a tunneling current through an additional probe junction. Our results demonstrate coherent operation and measurement of a quantum state of a single two-level system, i.e. a qubit, in a solid-state electronic device.

Y. Nakamura - One of the best experts on this subject based on the ideXlab platform.

  • Coherent control of macroscopic quantum states in a single-Cooper-pair box
    Nature, 1999
    Co-Authors: Y. Nakamura, Yuri A. Pashkin, J.-s. Tsai
    Abstract:

    A nanometre-scale superconducting electrode connected to a reservoir via a Josephson junction constitutes an artificial two-level electronic system: a single-Cooper-pair box. The two levels consist of charge states (differing by 2 e , where e is the electronic charge) that are coupled by tunnelling of Cooper pairs through the junction. Although the two-level system is macroscopic, containing a large number of electrons, the two charge states can be coherently superposed^ 1 , 2 , 3 , 4 . The Cooper-pair box has therefore been suggested^ 5 , 6 , 7 as a candidate for a quantum bit or ‘qubit’—the basic component of a quantum computer. Here we report the observation of quantum oscillations in a single-Cooper-pair box. By applying a Short Voltage Pulse via a gate electrode, we can control the coherent quantum state evolution: the Pulse modifies the energies of the two charge states non-adiabatically, bringing them into resonance. The resulting state—a superposition of the two charge states—is detected by a tunnelling current through a probe junction. Our results demonstrate electrical coherent control of a qubit in a solid-state electronic device.

  • Coherent control of macroscopic quantum states in a single-Cooper-pair box
    Nature, 1999
    Co-Authors: Y. Nakamura, Yuri A. Pashkin, J.-s. Tsai
    Abstract:

    5-7 as a candidate for a quantum bit or 'qubit'—the basic component of a quantum computer. Here we report the observation of quantum oscillations in a single- Cooper-pair box. By applying a Short Voltage Pulse via a gate electrode, we can control the coherent quantum state evolution: the Pulse modifies the energies of the two charge states non- adiabatically, bringing them into resonance. The resulting state— a superposition of the two charge states—is detected by a tunnelling current through a probe junction. Our results demon- strate electrical coherent control of a qubit in a solid-state

  • Coherent control of macroscopic quantum states in a single-Cooper-pair box
    Nature, 1999
    Co-Authors: Y. Nakamura, Yuri A. Pashkin, J.-s. Tsai
    Abstract:

    A small superconducting electrode (a single-Cooper-pair box) connected to a reservoir via a Josephson junction constitutes an artificial two-level system, in which two charge states that differ by 2e are coupled by tunneling of Cooper pairs. Despite its macroscopic nature involving a large number of electrons, the two-level system shows coherent superposition of the two charge states, and has been suggested as a candidate for a qubit, i.e. a basic component of a quantum computer. Here we report on time-domain observation of the coherent quantum-state evolution in the two-level system by applying a Short Voltage Pulse that modifies the energies of the two levels nonadiabatically to control the coherent evolution. The resulting state was probed by a tunneling current through an additional probe junction. Our results demonstrate coherent operation and measurement of a quantum state of a single two-level system, i.e. a qubit, in a solid-state electronic device.

Yuri A. Pashkin - One of the best experts on this subject based on the ideXlab platform.

  • Coherent control of macroscopic quantum states in a single-Cooper-pair box
    Nature, 1999
    Co-Authors: Y. Nakamura, Yuri A. Pashkin, J.-s. Tsai
    Abstract:

    A nanometre-scale superconducting electrode connected to a reservoir via a Josephson junction constitutes an artificial two-level electronic system: a single-Cooper-pair box. The two levels consist of charge states (differing by 2 e , where e is the electronic charge) that are coupled by tunnelling of Cooper pairs through the junction. Although the two-level system is macroscopic, containing a large number of electrons, the two charge states can be coherently superposed^ 1 , 2 , 3 , 4 . The Cooper-pair box has therefore been suggested^ 5 , 6 , 7 as a candidate for a quantum bit or ‘qubit’—the basic component of a quantum computer. Here we report the observation of quantum oscillations in a single-Cooper-pair box. By applying a Short Voltage Pulse via a gate electrode, we can control the coherent quantum state evolution: the Pulse modifies the energies of the two charge states non-adiabatically, bringing them into resonance. The resulting state—a superposition of the two charge states—is detected by a tunnelling current through a probe junction. Our results demonstrate electrical coherent control of a qubit in a solid-state electronic device.

  • Coherent control of macroscopic quantum states in a single-Cooper-pair box
    Nature, 1999
    Co-Authors: Y. Nakamura, Yuri A. Pashkin, J.-s. Tsai
    Abstract:

    5-7 as a candidate for a quantum bit or 'qubit'—the basic component of a quantum computer. Here we report the observation of quantum oscillations in a single- Cooper-pair box. By applying a Short Voltage Pulse via a gate electrode, we can control the coherent quantum state evolution: the Pulse modifies the energies of the two charge states non- adiabatically, bringing them into resonance. The resulting state— a superposition of the two charge states—is detected by a tunnelling current through a probe junction. Our results demon- strate electrical coherent control of a qubit in a solid-state

  • Coherent control of macroscopic quantum states in a single-Cooper-pair box
    Nature, 1999
    Co-Authors: Y. Nakamura, Yuri A. Pashkin, J.-s. Tsai
    Abstract:

    A small superconducting electrode (a single-Cooper-pair box) connected to a reservoir via a Josephson junction constitutes an artificial two-level system, in which two charge states that differ by 2e are coupled by tunneling of Cooper pairs. Despite its macroscopic nature involving a large number of electrons, the two-level system shows coherent superposition of the two charge states, and has been suggested as a candidate for a qubit, i.e. a basic component of a quantum computer. Here we report on time-domain observation of the coherent quantum-state evolution in the two-level system by applying a Short Voltage Pulse that modifies the energies of the two levels nonadiabatically to control the coherent evolution. The resulting state was probed by a tunneling current through an additional probe junction. Our results demonstrate coherent operation and measurement of a quantum state of a single two-level system, i.e. a qubit, in a solid-state electronic device.

Chihaya Adachi - One of the best experts on this subject based on the ideXlab platform.

  • quantification of temperature rise in unipolar organic conductors during Short Voltage Pulse excitation using electrical testing methods
    Organic Electronics, 2016
    Co-Authors: Kou Yoshida, Toshinori Matsushima, Hajime Nakanotani, Chihaya Adachi
    Abstract:

    Abstract To quantify the rise in device temperature caused by Joule heating during Short Voltage-Pulse excitation at high current densities (>10 A/cm2), the device temperatures of unipolar organic conductors were measured using electrical testing methods. For a maximum Voltage amplitude of 59 V at a current density of ∼300 A/cm2, temperature rose over 145 °C within a Pulse duration of 5 μs in an N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (α-NPD)-based single-carrier organic conductor. This result is in reasonable agreement with numerically calculated values. These findings indicate that suppressing the effects of Joule heating by carefully adjusting Pulse width, substrate and organic materials, and device configuration is important to achieve further carrier injection in the ultra-high current density region (>1 kA/cm2).

  • Effect of Joule heating on transient current and electroluminescence in p-i-n organic light-emitting diodes under Pulsed Voltage operation
    Organic Electronics, 2016
    Co-Authors: Kou Yoshida, Hajime Nakanotani, Chihaya Adachi
    Abstract:

    Abstract The transient current and electroluminescent characteristics of p-i-n organic light-emitting diodes driven using Short Voltage Pulses with various amplitudes and Pulse widths were investigated to understand high current behavior (>10 A/cm2). Even under Short Voltage Pulse operation, Joule heating was found to strongly affect the transient characteristics and lead to temperature rises estimated to be over 100 K in the high current density region (>400 A/cm2). This results in a large increase in both current density and EL intensity within the Pulse width. In addition, the Joule heating was found to have an effect on the external quantum efficiency. However its contribution was found to be limited compared with the other quenching mechanism, singlet-polaron quenching.

Alan C. West - One of the best experts on this subject based on the ideXlab platform.

  • Copper plating on titanium alloy 6-2-4-2 using an in situ high Voltage Pulse followed by plate-up
    Journal of Applied Electrochemistry, 2008
    Co-Authors: R. J. Gutfeld, Alan C. West
    Abstract:

    We have used an in situ technique that removes the oxide from the surface of the alloy titanium 6-2-4-2, followed by copper electroplating of the surface. The oxide removal is accomplished by means of a Short Voltage Pulse from a discharging capacitor between the cathode (titanium) and anode while submerged in the plating solution. Within seconds thereafter, the electrodes are switched to a separate power supply for electroplating copper onto the titanium. From the experimental data, we believe that the oxide is removed by means of dielectric breakdown mechanisms giving rise to a statistical probability that all of the surface oxide is removed. When this occurs, we obtain adherent depositions based on standard tape testing of the deposit. We determine a set of Voltage and energy density conditions which are most likely to result in good adhesion. Scanning electron micrographs of adherent copper deposits are presented.