Measuring and Suppressing Quantum State Leakage in a Superconducting Qubit.
نویسندگان
چکیده
Leakage errors occur when a quantum system leaves the two-level qubit subspace. Reducing these errors is critically important for quantum error correction to be viable. To quantify leakage errors, we use randomized benchmarking in conjunction with measurement of the leakage population. We characterize single qubit gates in a superconducting qubit, and by refining our use of derivative reduction by adiabatic gate pulse shaping along with detuning of the pulses, we obtain gate errors consistently below 10^{-3} and leakage rates at the 10^{-5} level. With the control optimized, we find that a significant portion of the remaining leakage is due to incoherent heating of the qubit.
منابع مشابه
Supplementary Information for “Measuring and Suppressing Quantum State Leakage in a Superconducting Qubit”
Zijun Chen,1 Julian Kelly,2 Chris Quintana,1 R. Barends,2 B. Campbell,1 Yu Chen,2 B. Chiaro,1 A. Dunsworth,1 A. G. Fowler,2 E. Lucero,2 E. Jeffrey,2 A. Megrant,1, 3 J. Mutus,2 M. Neeley,2 C. Neill,1 P. J. J. O’Malley,1 P. Roushan,2 D. Sank,2 A. Vainsencher,1 J. Wenner,1 T. C. White,1 A. N. Korotkov,4 and John M. Martinis1, 2, ∗ Department of Physics, University of California, Santa Barbara, Cal...
متن کاملDecoherence effects on quantum Fisher information of multi-qubit W states
Quantum fisher information of a parameter characterizing the sensitivity of a state with respect to parameter changes. In this paper, we study the quantum fisher information of the W state for four, five, six and seven particles in decoherence channels, such as amplitude damping, phase damping and depolarizing channel. Using Krauss operators for decoherence channels components, we investigate t...
متن کاملMicrowave-induced cooling of a superconducting qubit.
We demonstrated microwave-induced cooling in a superconducting flux qubit. The thermal population in the first-excited state of the qubit is driven to a higher-excited state by way of a sideband transition. Subsequent relaxation into the ground state results in cooling. Effective temperatures as low as approximately 3 millikelvin are achieved for bath temperatures of 30 to 400 millikelvin, a co...
متن کاملStrategies for Measuring the Decoherence Time of a Superconducting Qubit
The major roadblock to the development of a useful superconducting quantum coherent bit is decoherence. Integrating a flux-based qubit with Rapid Single Flux Quantum (RSFQ) electronics on a monolithic circuit provides a means to quickly prepare and measure the state of the qubit, thus enabling a number of qubit manipulations and interactions to take place within the qubit coherence time. Howeve...
متن کاملMulti-level quantum description of decoherence in superconducting qubits
We present a multi-level quantum theory of decoherence for a general circuit realization of a superconducting qubit. Using electrical network graph theory, we derive a Hamiltonian for the circuit. The dissipative circuit elements (external impedances, shunt resistors) are described using the Caldeira-Leggett model. The master equation for the superconducting phases in the BornMarkov approximati...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 116 2 شماره
صفحات -
تاریخ انتشار 2016