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1.
Nat Commun ; 15(1): 1714, 2024 Feb 24.
Article in English | MEDLINE | ID: mdl-38402235

ABSTRACT

Near continuous phase transitions, universal power-law scaling, characterized by critical exponents, emerges. This behavior reflects the singular responses of physical systems to continuous control parameters like temperature or external fields. Universal scaling extends to non-equilibrium dynamics in isolated quantum systems after a quench, where time takes the role of the control parameter. Our research unveils critical scaling in time also during the relaxation dynamics of an open quantum system. Here we experimentally realize such a system by the spin of individual Cesium atoms dissipatively coupled through spin-exchange processes to a bath of ultracold Rubidium atoms. Through a finite-size scaling analysis of the entropy dynamics via numerical simulations, we identify a critical point in time in the thermodynamic limit. This critical point is accompanied by the divergence of a characteristic length, which is described by critical exponents that turn out to be unaffected by system specifics.

2.
Int J Emerg Med ; 16(1): 92, 2023 Dec 21.
Article in English | MEDLINE | ID: mdl-38129781

ABSTRACT

BACKGROUND: Klebsiella pneumoniae invasion syndrome (KPIS) is a severe multi-site infection that is usually caused by hypervirulent Klebsiella pneumoniae. The bacteria are relatively common in Asian diabetics and can cause organ abscesses or sepsis. When patients develop intracranial infection, the prognosis is poor. After anti-infective treatment, the Klebsiella pneumoniae-induced liver and lung abscesses and pulmonary fungal infection were relieved, but the brain abscesses worsened. Such complex and severe infection cases are rarely reported. Early identification of intracranial infection, selection of antibiotics with high concentrations in cerebrospinal fluid, and active treatment of complications such as diabetes and fungal infection are of great significance for the prognosis of patients. CASE PRESENTATION: A 71-year-old patient diagnosed with liver abscess in another hospital was transferred to our hospital due to a worsening condition. On day 1 (day of admission), the patient was given invasive mechanical ventilation, continuous renal replacement therapy combined with endotoxin adsorption, antimicrobial treatment with imipenem-cilastatin, and percutaneous catheter drainage for liver abscess. Metagenomic next-generation sequencing in bronchoalveolar lavage fluid indicated Klebsiella pneumoniae (K. pneumoniae), Candida albicans, and Aspergillus flavus complex, and no viruses were detected. Blood and pus cultures revealed K. pneumoniae that was sensitive to piperacillin/tazobactam. The anti-infection therapy was adjusted to piperacillin/tazobactam combined with voriconazole. On day 14, a head computed tomography (CT) scan showed no significant changes, and a chest CT scan showed absorption of multiple abscesses in both lungs. The patient was still unconscious. After the endotracheal tube was removed, cranial magnetic resonance imaging (MRI) showed multiple brain abscesses. Finally, his family gave up, and the patient was discharged and died in a local hospital. CONCLUSION: In cases of K. pneumoniae infection, the possibility of intracranial, liver, lung, or other site infections should be considered, and physicians should be vigilant for the occurrence of KPIS. For patients suspected of developing an intracranial infection, cerebrospinal fluid should be tested and cultured as soon as possible, a head MRI should be performed, and antibiotics with high distribution in cerebrospinal fluid should be used early. When patients are complicated with diabetes, in addition to glycemic control, vigilance for concurrent fungal infections is also needed.

3.
Phys Rev Lett ; 131(7): 073201, 2023 Aug 18.
Article in English | MEDLINE | ID: mdl-37656843

ABSTRACT

Discrimination of entangled states is an important element of quantum-enhanced metrology. This typically requires low-noise detection technology. Such a challenge can be circumvented by introducing nonlinear readout process. Traditionally, this is realized by reversing the very dynamics that generates the entangled state, which requires a full control over the system evolution. In this Letter, we present nonlinear readout of highly entangled states by employing reinforcement learning to manipulate the spin-mixing dynamics in a spin-1 atomic condensate. The reinforcement learning found results in driving the system toward an unstable fixed point, whereby the (to be sensed) phase perturbation is amplified by the subsequent spin-mixing dynamics. Working with a condensate of 10 900 ^{87}Rb atoms, we achieve a metrological gain of 6.97_{-1.38}^{+1.30} dB beyond the classical precision limit. Our work will open up new possibilities in unlocking the full potential of entanglement caused quantum enhancement in experiments.

4.
Phytomedicine ; 92: 153726, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34536821

ABSTRACT

BACKGROUND: Isomeric ursolic acid (UA) and oleanolic acid (OA) compounds have recently garnered great attention due to their biological effects. Previously, it had been shown that UA and OA can exert important pharmacological action via the protein kinase C (PKC) and nuclear factor-κB (NF-κB) signaling, and that they can induce the expression of UDP-glucuronosyltransferase 1A1 (UGT1A1) in HepG2 cells. This study aims to investigate the role of PKC/NF-κB signaling in regulating the expression of UGT1A1 and examine how UA and OA induce UGT1A1 based on this signaling pathway. METHODS: HepG2 cells, hp65-overexpressed HepG2 cell and lentivirus-hp65-shRNA silenced HepG2 cells were stimulated with PKC/NF-κB specific agonists and inhibitors for 24 h in the presence or absence of UA and OA. The expression of UGT1A1, PKC, and NF-κB were determined by qRT-PCR, western blot, and dual-luciferase reporter gene assays. RESULTS: PKC/NF-κB activation downregulates UGT1A1 expression. This effect is countered by UA and OA treatment. Phorbol 12-myristate 13-acetate (PMA) and lipopolysaccharide (LPS), the agonists of PKC and NF-κB signaling, respectively, significantly inhibit hp65-mediated UGT1A1 luciferase activity. UA, OA, and the PKC/NF-κB inhibitors suppress this effect. PMA and LPS do not affect UGT1A1 activity in p65-silenced HepG2 cells; however, UA and OA mildly influence UGT1A1 expression in these cells. CONCLUSION: The activation of PKC/NF-κB signaling can significantly downregulate UGT1A1 expression. By inhibiting the PKC/NF-κB signaling pathway, UA and OA promote UGT1A1 expression in HepG2 cells.


Subject(s)
Oleanolic Acid , Glucuronosyltransferase , NF-kappa B/metabolism , Oleanolic Acid/pharmacology , Protein Kinase C/metabolism , Signal Transduction , Triterpenes , Up-Regulation , Ursolic Acid
5.
Phys Rev E ; 104(1-1): 014110, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34412241

ABSTRACT

Away from equilibrium, the properties of open quantum systems depend on the details of their environment. A microscopic derivation of a master equation (ME) is therefore crucial. Of particular interest are Lindblad-type equations, not only because they provide the most general class of Markovian MEs, but also since they are the starting point for efficient quantum trajectory simulations. Lindblad-type MEs are commonly derived from the Born-Markov-Redfield equation via a rotating-wave approximation (RWA). However the RWA is valid only for ultraweak system-bath coupling and often fails to accurately describe nonequilibrium processes. Here we derive an alternative Lindbladian approximation to the Redfield equation, which does not rely on ultraweak system-bath coupling. Applying it to an extended Hubbard model coupled to Ohmic baths, we show that, especially away from equilibrium, it provides a good approximation in large parameter regimes where the RWA fails.

6.
Biomed Pharmacother ; 133: 110939, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33232930

ABSTRACT

Shengmai Formula (SMF) is one of the traditional Chinese medicine representative formulas and is widely used for the treatment of cardio- and cerebrovascular disease. Previous studies demonstrated that the major effective ingredients in SMF can interact with each other based on some uptake transporters. However, the role of the efflux transporter breast cancer resistance protein (BCRP) in these interactions involving SMF remains unclear. The purpose of this study was to investigate the interactions of the major active components of SMF with BCRP and the compatibility mechanism of these complex components in SMF based on BCRP. We selected 4 main fractions, including ginseng total saponins (GTS), ophiopogon total saponins (OTS), ophiopogon total flavonoids (OTF), and fructus schisandrae total lignans (STL), and 12 bioactive components, including ginsenosides Re, Rd, Rb1, and Rg1, ophiopogonins D and D', methylophiopogonanones A and B, schizandrins A and B, and schizandrols A and B to explore the interactions of SMF with BCRP in LLC-PK1 and LLC-PK1/BCRP cells and BCRP membrane vesicles. The results showed that ginsenosides Re and Rg1, methylophiopogonanone B, and schizandrin A can be transported by BCRP into LLC-PK1/BCRP cells. Schisandrol B exhibited a markedly inhibitory effect on the transport function of BCRP and can significantly inhibit the uptake of methylophiopogonanone B and schizandrin A into LLC-PK1/BCRP cells. In "Inside-Out" BCRP membrane vesicles, BCRP mediated the transport of ginsenosides Re and Rg1, methylophiopogonanone B, and schizandrin A, with Km values of 111.9 ±â€¯31.26 µM, 82.01 ±â€¯16.72 µM, 57.06 ±â€¯8.789 µM, and 37.19 ±â€¯6.512 µM, respectively. GTS, STL, ginsenosides Rd and Rb1, and schisandrol B were potent inhibitors of BCRP and showed different degrees of inhibition on the transport of ginsenosides Re and Rg1, methylophiopogonanone B, and schizandrin A via BCRP. In conclusion, GTS, STL, ginsenosides Rd and Rb1, and schizandrol B are potential inhibitors of BCRP. Ginsenosides Re and Rg1, methylophiopogonanone B, and schizandrin A are potential substrates of BCRP, and their transport, which is mediated by BCRP, may be inhibited by potential inhibitors in SMF. There are potential interactions of these main effective components of SMF at the cellular and vesicular levels that are mediated by BCRP. The interplay of these bioactive components based on BCRP may be an important compatibility mechanism in SMF.


Subject(s)
ATP Binding Cassette Transporter, Subfamily G, Member 2/antagonists & inhibitors , Antineoplastic Agents, Phytogenic/pharmacology , Drugs, Chinese Herbal/pharmacology , Neoplasm Proteins/antagonists & inhibitors , Transport Vesicles/drug effects , ATP Binding Cassette Transporter, Subfamily G, Member 2/genetics , ATP Binding Cassette Transporter, Subfamily G, Member 2/metabolism , Animals , Antineoplastic Agents, Phytogenic/analysis , Antineoplastic Agents, Phytogenic/metabolism , Biological Transport , Drug Combinations , Drugs, Chinese Herbal/analysis , Drugs, Chinese Herbal/metabolism , LLC-PK1 Cells , Neoplasm Proteins/genetics , Neoplasm Proteins/metabolism , Swine , Transport Vesicles/genetics , Transport Vesicles/metabolism
7.
Cancer Manag Res ; 12: 5575-5585, 2020.
Article in English | MEDLINE | ID: mdl-32753970

ABSTRACT

BACKGROUND: Osteosarcoma (OS) is the most common primary bone tumor in group of children and adolescents. Increasing studies showed that long non-coding RNAs (lncRNAs) exerted important functions in the development of tumors, including OS. LINC01535 is an lncRNA which has been studied in cervical cancer but not in OS. AIM OF THE STUDY: This study was aimed to explore the biological function and mechanism of LINC01535 in OS. METHODS: LINC01535 expression was detected by qRT-PCR. Colony formation assay, EdU assay and CCK-8 assay were applied to check cell proliferation ability in OS. Flow cytometry analysis was conducted to measure cell apoptosis capacity. Wound healing assay and transwell assay were performed to assess cell migration and invasion. Luciferase reporter assay and RNA pull-down assay were carried out to verify the molecular mechanism. RESULTS: The high expression of LINC01535 was presented in OS tissues and cell lines compared with adjacent normal tissues and human osteoblasts. Moreover, OS patients with high LINC01535 expression exhibited poor prognosis. Loss-of-function assay revealed that silenced LINC01535 significantly attenuated cell proliferation, migration and invasion, and enhanced cell apoptosis in OS. Through mechanistic exploration, we found that LINC01535 interacted with miR-214-3p, and KCNC4 was validated to be a target gene of miR-214-3p. The levels of KCNC4 mRNA and protein were positively modulated by LINC01535 and reversely mediated by miR-214-3p. Based on rescue experiments, KCNC4 overexpression reserved the suppressive function of silenced LINC01535 on OS cell growth, migration and invasion. CONCLUSION: LINC01535, miR-214-3p and KCNC4 constituted an effective axis that exerted a pregnant regulation in OS development, which is a quite meaningful discovery for exploring potential therapeutic methods for OS patients.

8.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 34(7): 809-813, 2020 Jul 15.
Article in Chinese | MEDLINE | ID: mdl-32666720

ABSTRACT

OBJECTIVE: To investigate the effectiveness of volar oblique T-type locking plate and raft screws reduction and fixation in the treatment of extreme distal radius fractures. METHODS: Between July 2014 and July 2018, 15 patients with extreme distal radius fractures were treated with volar oblique T-type locking plate and raft screws reduction and fixation. There were 6 males and 9 females, aged from 30 to 66 years with an average age of 56.6 years. The cause of injury was falling from height in 2 cases and falling in 13 cases. All of them were fresh closed injuries. The fractures were rated as type 23C1 in 8 cases and as type 23C2 in 7 cases according to AO/Orthopaedic Trauma Association (AO/OTA) classification. There were 7 cases of ulnar styloid process fracture and 2 cases of distal radioulnar joint instability. The time from injury to operation was 6 to 9 days with an average of 7.3 days. The fracture healing and the radial height, palm inclination, and ulnar deviation were observed by X-ray reexamination. Cooney score was used to evaluate the effectiveness. RESULTS: All incisions healed by first intention. All patients were followed up 12-24 months, with an average of 14.6 months. X-ray films showed that all fractures healed, and the healing time ranged from 5 to 10 months, with an average of 8.2 months. No internal fixation failure or secondary fracture displacement occurred. At last follow-up, the radial height, palm inclination, and ulnar deviation recovered well, and the differences between pre- and post-operation were significant ( P<0.05). The pain, function, activity, and grip strength scores and the total score of Cooney score were significantly higher than those before operation ( P<0.05). There were 11 cases of excellent, 3 cases of good, and 1 case of good, with an excellent and good rate of 93%. CONCLUSION: For extreme distal radius fractures, the volar oblique T-type locking plate and raft screws reduction and fixation can restore the radialheight, palm inclination, and ulnar deviation, fix firmly, and recover the wrist joint function exercise early, and obtain satisfactory effectiveness.


Subject(s)
Radius Fractures , Ulna Fractures , Adult , Aged , Bone Plates , Female , Fracture Fixation, Internal , Humans , Male , Middle Aged , Range of Motion, Articular , Treatment Outcome , Wrist Joint
9.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 34(4): 457-462, 2020 Apr 15.
Article in Chinese | MEDLINE | ID: mdl-32291981

ABSTRACT

OBJECTIVE: To investigate the effectiveness of closed or limited open reduction and intramedullary nail fixation in the treatment of Seinsheimer type Ⅴ subtrochanteric fracture. METHODS: Between May 2014 and July 2018, 36 patients with Scinsheimer type Ⅴ subtrochanteric fractures were treated with closed or limited open reduction and intramedullary nail fixation. There were 25 males and 11 females with an age of 23-86 years (mean, 55.8 years). The cause of injury included falling in 19 cases, traffic accident in 9 cases, falling from height in 7 cases, and heavy object injury in 1 case; all were fresh closed injuries. The interval between injury and operation was 1-14 days (mean, 6.8 days). There were 18 cases of closed reduction and 18 cases of limited open reduction during the operation. Seventeen cases were fixed with femoral reconstruction intramedullary nail, 5 with InterTan long nail, 14 with lengthened proximal femoral nail anti-rotation, and 7 cases were assisted with auxiliary steel wire binding. After operation, through X-ray film and clinical follow-up, the fracture reduction and maintenance status, internal fixation position, and fracture healing were judged; the range of motion, walking ability, and complications of hip joint were observed, and the function of hip joint was evaluated according to Merle d'Aubigne Postel hip joint scoring standard. RESULTS: All the incisions of medullary operation healed by first intention, and no vascular, nerve injury, or infection occurred. All patients were followed up 12-24 months, with an average of 14.2 months. Among the 36 patients, 1 patient received revision surgery due to varus displacement of femoral head and screw penetration at 2 months after closed reduction, with poor recovery of hip function. X-ray film re-examination showed that the fractures of the other 35 patients healed after 9-15 months, with an average of 11.5 months. During follow-up, there was no complication such as internal fixation failure, fracture redisplacement, bone nonunion or malunion, and deep vein thrombosis of lower extremity occurred. The function of hip joint recovered well, and the patients could walk and squat normally without affecting daily life or work. At last follow-up, according to Merle d'Aubigne Postel hip joint scoring standard, 28 cases were rated as excellent, 4 cases as good, 3 cases as fair, and 1 case as poor, the excellent and good rate was 88.9%. CONCLUSION: C-arm X-ray fluoroscopic closed or limited open reduction and intramedullary nail fixation for the treatment of Seinheimer Ⅴ type subtrochanteric fracture, if necessary, with the aid of auxiliary steel wire binding, it has the advantages of less blood supply destruction at the fracture end, satisfactory reduction, firm fixation, and early rehabilitation training, with definite effectiveness.


Subject(s)
Bone Nails , Fracture Fixation, Internal , Fracture Fixation, Intramedullary , Hip Fractures/surgery , Adult , Aged , Aged, 80 and over , Bone Screws , Female , Fracture Healing , Humans , Male , Middle Aged , Treatment Outcome , Young Adult
10.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 34(3): 347-351, 2020 Mar 15.
Article in Chinese | MEDLINE | ID: mdl-32174081

ABSTRACT

OBJECTIVE: To investigate the effectiveness of open reduction and internal fixation for multiple injuries of superior shoulder suspensory complex (SSSC) with coracoid process fracture. METHODS: Between January 2014 and October 2018, 22 patients with multiple injuries of SSSC with coracoid process fracture were treated by open reduction and internal fixation. There were 16 males and 6 females, aged from 24 to 72 years with an average age of 36.6 years. There were 10 cases of falling injury, 5 cases of traffic accident injury, and 7 cases of falling from height injury. All of them were fresh closed injuries. The time from injury to operation ranged from 2 to 17 days with an average of 6.9 days. Both X-ray film and CT showed the coracoid process fracture complicated with clavicular fracture in 14 cases, acromioclavicular joint dislocation in 12 cases, and acromioclavicular fracture in 5 cases. There were 14 cases of two places of SSSC, 7 cases of three places of SSSC, and 1 case of four places of SSSC. RESULTS: All incisions healed in primary stage after operation. All patients were followed up 10-24 months with an average of 14.1 months. X-ray films showed that all fractures healed and the acromioclavicular joint was normal. The healing time ranged from 6 to 12 months, with an average of 6.2 months. No complications such as internal fixation failure and nonunion occurred. According to University of California Los Angeles (UCLA) shoulder scoring system, the shoulder joint function was rated as excellent in 15 cases, good in 5 cases, and poor in 2 cases at last follow-up. The excellent and good rate was 90.9%. CONCLUSION: Open reduction and internal fixation for treatment of multiple injuries of SSSC with coracoid process fracture is firm and reliable. Combined with active postoperative rehabilitation program intervention, it can accelerate the recovery of shoulder joint function and achieve satisfactory effectiveness.


Subject(s)
Coracoid Process/injuries , Coracoid Process/surgery , Fracture Fixation, Internal , Fractures, Bone/surgery , Multiple Trauma/surgery , Shoulder Injuries/surgery , Adult , Aged , Female , Humans , Male , Middle Aged , Shoulder/surgery , Treatment Outcome , Young Adult
11.
Phys Rev Lett ; 123(3): 030602, 2019 Jul 19.
Article in English | MEDLINE | ID: mdl-31386479

ABSTRACT

We investigate the relaxation dynamics of an interacting Stark-localized system coupled to a dephasing bath, and compare its behavior to the conventional disorder-induced many body localized system. Specifically, we study the dynamics of population imbalance between even and odd sites, and the growth of the von Neumann entropy. For a large potential gradient, the imbalance is found to decay on a timescale τ that grows quadratically with the Wannier-Stark tilt. For the noninteracting system, it shows an exponential decay, which becomes a stretched exponential decay in the presence of finite interactions. This is different from a system with disorder-induced localization, where the imbalance exhibits a stretched exponential decay also for vanishing interactions. As another clear qualitative difference, we do not find a logarithmically slow growth of the von Neumann entropy as it is found for the disordered system. Our findings can immediately be tested experimentally with ultracold atoms in optical lattices.

12.
Phytomedicine ; 59: 152916, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30978651

ABSTRACT

BACKGROUND: Shengmai Formula (SMF) is widely used to treat cardiovascular disease such as chronic heart disease, coronary atherosclerotic heart disease, viral myocarditis, and others. Our previous studies have shown that OATP1B1/1B3 mediates the interactions between ophiopogon D and ginsenoside Rb1/Rd, which are the major active components in SMF. The herb-drug interactions that involve sodium taurocholate co-transporting polypeptide (NTCP) have been drawing increasing amounts of attention. PURPOSE: The aim of the present study was to investigate the interactions of the major effective components in SMF mediated by NTCP. METHODS: By using NTCP-overexpressing HEK293T cells and liquid chromatograph-mass spectrometer (LC-MS) analytical methods, we investigated the impact of the four main effective fractions and the 12 main effective components in SMF on NTCP-mediated sodium taurocholate (TCNa) uptake. The interactions of these effective components in SMF mediated by NTCP were further studied. RESULTS: The main effective fractions, ginseng total saponins (GTS), ophiopogon total saponins (OTS), ophiopogon total flavonoids (OTF), and fructus schisandrae total lignans (STL), all exhibited a certain inhibitory effect on the uptake of TCNa. Among the 12 main effective components, only ginsenoside Rg1, ophiopogon D', and schizandrin A showed inhibition of TCNa uptake, with IC50 values of 50.49 ± 4.24 µM, 6.71 ± 0.70 µM, and 45.80 ± 3.10 µM, respectively. Additionally, we found that ginsenoside Re and schizandrin B could be transported by NTCP-overexpressing HEK293T cells, and that the uptake of ginsenoside Re was significantly inhibited by OTS, OTF, STL, ginsenoside Rg1, ophiopogon D', and schizandrin A. The uptake of schizandrin B was significantly inhibited by GTS, OTS, OTF, and ophiopogon D'. CONCLUSION: Ginsenoside Rg1, ophiopogon D', and schizandrin A are potential inhibitors of NTCP and may interact with clinical drugs mediated by NTCP. Ginsenoside Re and schizandrin B are also potential substrates of NTCP, and their uptake mediated by NTCP was inhibited by the other components in SMF. The interaction of complex components based on NTCP may be one of the important compatibility mechanisms in SMF.


Subject(s)
Drugs, Chinese Herbal/pharmacology , Organic Anion Transporters, Sodium-Dependent/metabolism , Symporters/metabolism , Biological Transport/drug effects , Biological Transport/physiology , Chromatography, Liquid , Drug Combinations , HEK293 Cells , Humans , Mass Spectrometry
13.
Proc Natl Acad Sci U S A ; 115(25): 6381-6385, 2018 06 19.
Article in English | MEDLINE | ID: mdl-29858344

ABSTRACT

Interferometry is a paradigm for most precision measurements. Using N uncorrelated particles, the achievable precision for a two-mode (two-path) interferometer is bounded by the standard quantum limit (SQL), [Formula: see text], due to the discrete (quanta) nature of individual measurements. Despite being a challenging benchmark, the two-mode SQL has been approached in a number of systems, including the Laser Interferometer Gravitational-Wave Observatory and today's best atomic clocks. For multimode interferometry, the SQL becomes [Formula: see text] using M modes. Higher precision can also be achieved using entangled particles such that quantum noises from individual particles cancel out. In this work, we demonstrate an interferometric precision of [Formula: see text] dB beyond the three-mode SQL, using balanced spin-1 (three-mode) Dicke states containing thousands of entangled atoms. The input quantum states are deterministically generated by controlled quantum phase transition and exhibit close to ideal quality. Our work shines light on the pursuit of quantum metrology beyond SQL.

14.
Sci Rep ; 7: 46756, 2017 04 27.
Article in English | MEDLINE | ID: mdl-28447670

ABSTRACT

Spin-orbit coupling (SOC) plays an essential role in many exotic and interesting phenomena in condensed matter physics. In neutral-atom-based quantum simulations, synthetic SOC constitutes a key enabling element. The strength of SOC realized so far is limited by various reasons or constraints. This work reports tunable SOC synthesized with a gradient magnetic field (GMF) for atoms in a harmonic trap. Nearly ten-fold enhancement is observed when the GMF is modulated near the harmonic-trap resonance in comparison with the free-space situation. A theory is developed that well explains the experimental results. Our work offers a clear physical insight into and analytical understanding of how to tune the strength of atomic SOC synthesized with GMF using harmonic trap resonance.

15.
Science ; 355(6325): 620-623, 2017 02 10.
Article in English | MEDLINE | ID: mdl-28183976

ABSTRACT

Many-body entanglement is often created through the system evolution, aided by nonlinear interactions between the constituting particles. These very dynamics, however, can also lead to fluctuations and degradation of the entanglement if the interactions cannot be controlled. Here, we demonstrate near-deterministic generation of an entangled twin-Fock condensate of ~11,000 atoms by driving a arubidium-87 Bose-Einstein condensate undergoing spin mixing through two consecutive quantum phase transitions (QPTs). We directly observe number squeezing of 10.7 ± 0.6 decibels and normalized collective spin length of 0.99 ± 0.01. Together, these observations allow us to infer an entanglement-enhanced phase sensitivity of ~6 decibels beyond the standard quantum limit and an entanglement breadth of ~910 atoms. Our work highlights the power of generating large-scale useful entanglement by taking advantage of the different entanglement landscapes separated by QPTs.

16.
Sci Rep ; 6: 18983, 2016 Jan 11.
Article in English | MEDLINE | ID: mdl-26752786

ABSTRACT

We report the observation of synthesized spin-orbit coupling (SOC) for ultracold spin-1 (87)Rb atoms. Different from earlier experiments where a one dimensional (1D) atomic SOC of pseudo-spin-1/2 is synthesized with Raman laser fields, the scheme we demonstrate employs a gradient magnetic field (GMF) and ground-state atoms, thus is immune to atomic spontaneous emission. The strength of SOC we realize can be tuned by changing the modulation amplitude of the GMF, and the effect of the SOC is confirmed through the studies of: 1) the collective dipole oscillation of an atomic condensate in a harmonic trap after the synthesized SOC is abruptly turned on; and 2) the minimum energy state at a finite adiabatically adjusted momentum when SOC strength is slowly ramped up. The condensate coherence is found to remain very good after driven by modulating GMFs. Our scheme presents an alternative means for studying interacting many-body systems with synthesized SOC.

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