Abstract
Charge qubits formed in double quantum dots represent quintessential two-level systems that enjoy both ease of control and efficient readout. Unfortunately, charge noise can cause rapid decoherence, with typical single-qubit gate fidelities falling below 90%. Here we develop analytical methods to study the evolution of strongly driven charge qubits, for general and 1/f charge-noise spectra. We show that special pulsing techniques can simultaneously suppress errors due to strong driving and charge noise, yielding single-qubit gates with fidelities above 99.9%. These results demonstrate that quantum dot charge qubits provide a potential route to high-fidelity quantum computation.
Highlights
Building high-quality qubits is a key objective in quantum information processing
We demonstrate our method on a double-quantum-dot charge qubit, showing that high-fidelity gate operations can be achieved in charge qubits under strong driving, even while 1/f noise is applied to the double-dot detuning parameter
To differentiate the effects of decoherence from those arising from strong driving, we present the same results in an interaction frame defined by U0, ρI 1⁄4 U0yρU0, in which the fast oscillations due to strong driving are not observed
Summary
Building high-quality qubits is a key objective in quantum information processing. Achieving high-fidelity gates requires both precise control and effective measures to combat decoherence arising from the environment. One strategy for achieving higher fidelities is to operate the qubits as fast as possible, for example, by driving them with strong microwaves. We propose an alternative control scheme for strong driving, based on rectangular pulse envelopes engineered to produce nodes in the fast oscillations at the end of a gate operation, thereby minimizing their influence. We demonstrate our method on a double-quantum-dot charge qubit, showing that high-fidelity gate operations can be achieved in charge qubits under strong driving, even while 1/f noise is applied to the double-dot detuning parameter. This noise spectrum is interesting because it has both Markovian and non-
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