Measuring the Berry phase in a superconducting phase qubit by a shortcut to adiabaticity

Abstract

With a counter-diabatic field supplemented to the reference control field, the 'shortcut to adiabaticiy' (STA) protocol is implemented in a superconducting phase qubit. The Berry phase measured in a short time scale is in good agreement with the theoretical result acquired from an adiabatic loop. The trajectory of a qubit vector is extracted, verifying the Berry phase alternatively by the integrated solid angle. The classical noise is introduced to the amplitude or phase of the total control field. The mean of the Berry phase measured under either noise is almost equal to that without noise, while the variance under the amplitude noise can be described by an analytical expression. * yiyin@zju.edu.cn

Robust and highly efficient discrimination of chiral molecules through three-mode parallel paths

“…The required respective phases of the three pulses can be determined by setting the phases of the corresponding fields. Recently, many microwave-regime experiments of the pulse shaping including the modulations of amplitudes, frequencies and phases (flip) by means of arbitrary waveform generators have been reported [54][55][56][57][58][59][60]. The electric dipole moments of the considered transitions are of 1 Debye order, and it is securable to control the Rabi frequencies within 0-10 MHz by using the maximum field strength around ∼ 2 V /cm.…”

The experimental realization of high-fidelity ‘shortcut-to-adiabaticity’ quantum gates in a superconducting Xmon qubit

“…x y z is the vector of Pauli matrices. The amplitude Ω(t), the polar angle θ(t) and the azimuthal angle f(t) are modulated by microwave pulse sequences in our experiment [23,24]. At a given time t, the instantaneous eigenstates, y y ñ ñ + -…”

Experimental demonstration of work fluctuations along a shortcut to adiabaticity with a superconducting Xmon qubit

“…Therefore, it is straightforward to expect a connection between the STA excess of work fluctuations and a quantum geometric quantity. As shown in section 2.2, this connection is described by the equality in equation (16) [32], which is further simplified to be equation (19) for a single-qubit system. To verify equation (19), we first experimentally determine the STA excess of work fluctuations with the operation time T. Since the second moments for both initial eigenstates are theoretically identical, only W t m [ (˜)˜] with different operation times also fall into a single curve from the theoretical prediction, although experimental errors are found.…”

“…Soon after the theoretical proposal, experimental implementation has been executed in various quantum devices [14][15][16][17][18][19][20][21]. In our recent studies, we have applied the STA protocol in a superconducting qubit for the realization of a Berry phase measurement [19], quantum state transfer [20] and high-fidelity gates [21]. The STA protocol was also used by us to simulate topological phase transition through an experimental construction of the first Brillouin zone [20].…”