Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of Physics Conference Series

Study of microwave-induced phase switches from the finite voltage state in Bi2Sr2CaCu2Oyintrinsic Josephson junctions

Haruhisa Kitano, Ayami Yamaguchi, Yusaku Takahashi, Daiki Kakehi, Shin-ya Ayukawa

Published Jul 1, 2017• 3 citations
Publisher

Abstract

We study the microwave-induced phase switches from the finite voltage state for the underdamped intrinsic Josephson junctions (IJJs) made of Bi 2 Sr 2 CaCu 2 O y (Bi2212). We observe the resonant double-peak structure in the switching current distribution at low temperatures. This feature is successfully explained by a quantum mechanical model where the strong microwave field effectively suppresses the potential barrier for the phase escape from a potential well and the macroscopic quantum tunneling (MQT) is resonantly enhanced. The detailed analyses considering the effects of multiple phase retrapping processes after the phase escape strongly suggest that the intense microwave field suppresses the energy-level spacing in the potential well, by effectively decreasing the fluctuation-free critical current and the Josephson plasma frequency. This effect also reduces the number of photons required for the multiphoton transition between the ground and the first excited states, making it possible to observe the energy level quantization in the MQT state. The temperature dependence of the resonance peak emerging in the switching rate clearly demonstrates that the quantized energy state can be survived up to ~10 K, which is much higher than a crossover temperature predicted by the conventional Caldeira-Leggett theory.

DOI
10.1088/1742-6596/871/1/012008

Related papers

Enhancement of macroscopic quantum tunneling in the higher-order phase switches of Bi2212 intrinsic Josephson junctions

Haruhisa Kitano, Ayami Yamaguchi, Yusaku Takahashi +5 more

The macroscopic quantum tunneling (MQT) in the current-biased intrinsic Josephson junctions (IJJs) of high- T c cuprates has attracted much attention for decades. Although the MQT for the phase switches from the zero to the first voltage state (1st SW) in the multiple-branched I-V curves is well explained by the conventional theory, the occurrence of MQT for the higher order switches such as the switch from the 1st to 2nd voltage state (2nd SW) has been still debated. Here, we present an experimental study on the phase switches of small IJJs fabricated from underdoped Bi 2 Sr 2 (Ca,Y)Cu 2 O y . We observed the single photon transition between quantized energy levels in the 3rd phase switches at 59.15 GHz and 2 K. The comparison with the previous studies on the nearly optimal-doped Bi 2 Sr 2 CaCu 2 O y clearly suggests a possibility that the MQT rate for the higher-order phase switches is commonly enhanced by the effective suppression of the energy barrier for the higher-order phase escape due to the phase-running state after the 1st SW, in spite of the large difference in a critical current density and T c .

Journal of Physics Conference Series•Mar 1, 2018•2 citations

Resonant Phase Escape from the First Resistive State of Bi2Sr2CaCu2Oy Intrinsic Josephson Junctions under Strong Microwave Irradiation

Yusaku Takahashi, Daiki Kakehi, Shuho Takekoshi +3 more

We report a study of the phase escape in Bi2Sr2CaCu2Oy intrinsic Josephson junctions under the strong microwave irradiation, focusing on the switch from the first resistive state (2nd SW). The resonant double-peak structure is clearly observed in the switching current distributions below 10 K and is successfully explained by a quantum-mechanical model on the quantum phase escape under the strong microwave field. These results provide the first evidence for the formation of the energy level quantization for the 2nd SW, supporting that the macroscopic quantum tunneling for the 2nd SW survives up to ∼10 K.

Journal of the Physical Society of Japan•Jun 3, 2016•8 citations

Resonant phase escape in Bi2Sr2CaCu2O8+δsurface intrinsic Josephson junctions

Haifeng Yu, Xiaobo Zhu, Jian-kun Ren +10 more

We present a study of phase escape in surface Bi 2 Sr 2 CaCu 2 O 8+ δ intrinsic Josephson junctions in the presence of microwave radiation. The measured switching current distributions display clear double-peak structures in the microwave field, which result from the single- and two-photon resonant escape processes accompanied by microwave-induced potential barrier suppression. We show that these results can be well explained by a quantum-mechanical model proposed by Fistul et al (2003 Phys. Rev. B 68 060504), from which the power and frequency dependences of the switching current distributions can be reproduced.

New Journal of Physics•Sep 16, 2013•5 citations

Macroscopic quantum tunneling and thermal activation in a small mesa structured Bi2Sr2CaCu2Oyintrinsic Josephson junctions

Haruhisa Kitano, K. Ota, Kenji Hamada +4 more

A nanometer-thick small mesa consiting of only two or three Bi 2 Sr 2 CaCu 2 O y intrinsic Josephson junctions (IJJs) is studied through the switching current distribution measurements down to 0.4 K. Experimental results clearly show that the first switching events from the zero-voltage state for 1 K < T < 4 K are successfully described by a conventional thermal activation (TA) theory for a single Josephson junction, and that they become independent of temperature below T* ∼ 0.7 K. We observe the microwave-induced peak in the switching distribution at 0.4 K, which is induced by the microwave irradiation at 55 GHz. These results strongly suggest that the system crossovers to macroscopic quantum tunneling (MQT) regime below T* , which is as high as the previously reported value for a stacked IJJs with several tens of junctions, in contrast to the recent result on a similar mesa-structured surface IJJ.

Journal of Physics Conference Series•Mar 1, 2009•0 citations

Comparative study of macroscopic quantum tunneling in Bi2Sr2CaCu2Oy intrinsic Josephson junctions with different device structures

K. Ota, Kenji Hamada, Ryota Takemura +6 more

We investigated macroscopic quantum tunneling (MQT) of ${\text{Bi}}_{2}{\text{Sr}}_{2}{\text{CaCu}}_{2}{\text{O}}_{y}$ intrinsic Josephson junctions (IJJs) for two device structures. One is a small mesa, which is a few nanometers thick with only two or three IJJs, and the other is a stack of a few hundred IJJs in a narrow bridge structure. The experimental results regarding the switching-current distribution for the first switch from the zero-voltage state were in good agreement with the conventional theory for a single Josephson junction, indicating that the crossover temperature from thermal activation to the MQT regime for the former device structure was similar to that for the latter device structure. Together with the observation of multiphoton transitions between quantized energy levels in the MQT regime, these results strongly suggest that the observed MQT behavior is intrinsic to a single IJJ in high-${T}_{c}$ cuprates and is independent of the device structure. The switching-current distribution for the second switch from the first resistive state, which was carefully distinguished from the first switch, was also compared with respect to the two device structures. In spite of the differences between the heat transfer environments, the second switch exhibited a similar temperature-independent behavior for both devices up to a much higher temperature than the crossover temperature for the first switch. We argue that this cannot be explained in terms of self-heating caused by dissipative currents after the first switch. As possible candidates for this phenomenon, the MQT process for the second switch and the effective increase in the electronic temperature due to the quasiparticle injection are discussed.

arXiv:0807.1194•Physical Review B•Apr 3, 2009•41 citations

Increase of Phase Retrapping Effects in the Switching Rate from the Finite Voltage State of the Underdamped Intrinsic Josephson Junctions

Haruhisa Kitano, Yusaku Takahashi, Daiki Kakehi +3 more

We report a detailed study of the phase switching rate from the first to the fourth switch for a small stack of Bi2Sr2CaCu2Oy intrinsic Josephson junctions (IJJs). Experimental results were analyzed by using the conventional single-junction model including the thermally-activated phase escape and the multiple phase retrapping. It is shown that the phase retrapping effects are more prominent for higher order switches, even for the underdamped IJJs showing a large hysteresis in the current–voltage characteristics. This clearly suggests that the tilted washboard potential representing the phase switch from the finite voltage state in IJJs can be influenced by a rapid oscillation generated in a phase-switched junction.

Journal of the Physical Society of Japan•Apr 14, 2016•11 citations
We study the microwave-induced phase switches from the finite voltage state for the underdamped intrinsic Josephson junctions (IJJs) made of Bi 2 Sr 2 CaCu 2 O y (Bi2212). We observe the resonant double-peak structure in the switching current distribution at low temperatures. This feature is successfully explained by a quantum mechanical model where the strong microwave field effectively suppresses the potential barrier for the phase escape from a potential well and the macroscopic quantum tunneling (MQT) is resonantly enhanced. The detailed analyses considering the effects of multiple phase retrapping processes after the phase escape strongly suggest that the intense microwave field suppresses the energy-level spacing in the potential well, by effectively decreasing the fluctuation-free critical current and the Josephson plasma frequency. This effect also reduces the number of photons required for the multiphoton transition between the ground and the first excited states, making it possible to observe the energy level quantization in the MQT state. The temperature dependence of the resonance peak emerging in the switching rate clearly demonstrates that the quantized energy state can be survived up to ~10 K, which is much higher than a crossover temperature predicted by the conventional Caldeira-Leggett theory.
The macroscopic quantum tunneling (MQT) in the current-biased intrinsic Josephson junctions (IJJs) of high- T c cuprates has attracted much attention for decades. Although the MQT for the phase switches from the zero to the first voltage state (1st SW) in the multiple-branched I-V curves is well explained by the conventional theory, the occurrence of MQT for the higher order switches such as the switch from the 1st to 2nd voltage state (2nd SW) has been still debated. Here, we present an experimental study on the phase switches of small IJJs fabricated from underdoped Bi 2 Sr 2 (Ca,Y)Cu 2 O y . We observed the single photon transition between quantized energy levels in the 3rd phase switches at 59.15 GHz and 2 K. The comparison with the previous studies on the nearly optimal-doped Bi 2 Sr 2 CaCu 2 O y clearly suggests a possibility that the MQT rate for the higher-order phase switches is commonly enhanced by the effective suppression of the energy barrier for the higher-order phase escape due to the phase-running state after the 1st SW, in spite of the large difference in a critical current density and T c .
We report a study of the phase escape in Bi2Sr2CaCu2Oy intrinsic Josephson junctions under the strong microwave irradiation, focusing on the switch from the first resistive state (2nd SW). The resonant double-peak structure is clearly observed in the switching current distributions below 10 K and is successfully explained by a quantum-mechanical model on the quantum phase escape under the strong microwave field. These results provide the first evidence for the formation of the energy level quantization for the 2nd SW, supporting that the macroscopic quantum tunneling for the 2nd SW survives up to ∼10 K.
We present a study of phase escape in surface Bi 2 Sr 2 CaCu 2 O 8+ δ intrinsic Josephson junctions in the presence of microwave radiation. The measured switching current distributions display clear double-peak structures in the microwave field, which result from the single- and two-photon resonant escape processes accompanied by microwave-induced potential barrier suppression. We show that these results can be well explained by a quantum-mechanical model proposed by Fistul et al (2003 Phys. Rev. B 68 060504), from which the power and frequency dependences of the switching current distributions can be reproduced.
A nanometer-thick small mesa consiting of only two or three Bi 2 Sr 2 CaCu 2 O y intrinsic Josephson junctions (IJJs) is studied through the switching current distribution measurements down to 0.4 K. Experimental results clearly show that the first switching events from the zero-voltage state for 1 K < T < 4 K are successfully described by a conventional thermal activation (TA) theory for a single Josephson junction, and that they become independent of temperature below T* ∼ 0.7 K. We observe the microwave-induced peak in the switching distribution at 0.4 K, which is induced by the microwave irradiation at 55 GHz. These results strongly suggest that the system crossovers to macroscopic quantum tunneling (MQT) regime below T* , which is as high as the previously reported value for a stacked IJJs with several tens of junctions, in contrast to the recent result on a similar mesa-structured surface IJJ.
We investigated macroscopic quantum tunneling (MQT) of Bi2Sr2CaCu2Oy{\text{Bi}}_{2}{\text{Sr}}_{2}{\text{CaCu}}_{2}{\text{O}}_{y}Bi2​Sr2​CaCu2​Oy​ intrinsic Josephson junctions (IJJs) for two device structures. One is a small mesa, which is a few nanometers thick with only two or three IJJs, and the other is a stack of a few hundred IJJs in a narrow bridge structure. The experimental results regarding the switching-current distribution for the first switch from the zero-voltage state were in good agreement with the conventional theory for a single Josephson junction, indicating that the crossover temperature from thermal activation to the MQT regime for the former device structure was similar to that for the latter device structure. Together with the observation of multiphoton transitions between quantized energy levels in the MQT regime, these results strongly suggest that the observed MQT behavior is intrinsic to a single IJJ in high-Tc{T}_{c}Tc​ cuprates and is independent of the device structure. The switching-current distribution for the second switch from the first resistive state, which was carefully distinguished from the first switch, was also compared with respect to the two device structures. In spite of the differences between the heat transfer environments, the second switch exhibited a similar temperature-independent behavior for both devices up to a much higher temperature than the crossover temperature for the first switch. We argue that this cannot be explained in terms of self-heating caused by dissipative currents after the first switch. As possible candidates for this phenomenon, the MQT process for the second switch and the effective increase in the electronic temperature due to the quasiparticle injection are discussed.
We report a detailed study of the phase switching rate from the first to the fourth switch for a small stack of Bi2Sr2CaCu2Oy intrinsic Josephson junctions (IJJs). Experimental results were analyzed by using the conventional single-junction model including the thermally-activated phase escape and the multiple phase retrapping. It is shown that the phase retrapping effects are more prominent for higher order switches, even for the underdamped IJJs showing a large hysteresis in the current–voltage characteristics. This clearly suggests that the tilted washboard potential representing the phase switch from the finite voltage state in IJJs can be influenced by a rapid oscillation generated in a phase-switched junction.