Efficient simulation of Gottesman-Kitaev-Preskill states with Gaussian circuits

We study the classical simulatability of Gottesman-Kitaev-Preskill (GKP) states in combination with arbitrary displacements, a large set of symplectic operations and homodyne measurements. For these types of circuits, neither continuous-variable theorems based on the non-negativity of quasi-probability distributions nor discrete-variable theorems such as the Gottesman-Knill theorem can be employed to assess the simulatability. We first develop a method to evaluate the probability density function corresponding to measuring a single GKP state in the position basis following arbitrary squeezing and a large set of rotations. This method involves evaluating a transformed Jacobi theta function using techniques from analytic number theory. We then use this result to identify two large classes of multimode circuits which are classically efficiently simulatable and are not contained by the GKP encoded Clifford group. Our results extend the set of circuits previously known to be classically efficiently simulatable

The aging process and potential interventions to extend life expectancy

Aging is commonly defined as the accumulation of diverse deleterious changes occurring in cells and tissues with advancing age that are responsible for the increased risk of disease and death. The major theories of aging are all specific of a particular cause of aging, providing useful and important insights for the understanding of age-related physiological changes. However, a global view of them is needed when debating of a process which is still obscure in some of its aspects. In this context, the search for a single cause of aging has recently been replaced by the view of aging as an extremely complex, multifactorial process. Therefore, the different theories of aging should not be considered as mutually exclusive, but complementary of others in the explanation of some or all the features of the normal aging process. To date, no convincing evidence showing the administration of existing “anti-aging” remedies can slow aging or increase longevity in humans is available. Nevertheless, several studies on animal models have shown that aging rates and life expectancy can be modified. The present review provides an overlook of the most commonly accepted theories of aging, providing current evidence of those interventions aimed at modifying the aging process

Sufficient condition for universal quantum computation using bosonic circuits

We present a new method for quantifying the resourcefulness of continuous-variable states in the context of promoting otherwise simulatable circuits to universality. The simulatable, albeit non-Gaussian, circuits that we consider are composed of Gottesman-Kitaev-Preskill states, Gaussian operations, and homodyne measurements. We first introduce a general framework for mapping a continuous-variable state into a qubit state. We then express existing maps in this framework, including the modular subsystem decomposition and stabilizer subsystem decomposition. Combining these results with existing results in discrete-variable quantum computation provides a sufficient condition for achieving universal quantum computation. These results also allow us to demonstrate that for states symmetric in the position representation, the modular subsystem decomposition can be interpreted in terms of resourceless (simulatable) operations - i.e., included in the class of Gaussian circuits with input stabilizer Gottesman-Kitaev-Preskill states. Therefore, the modular subsystem decomposition is an operationally relevant mapping to analyze the logical content of realistic Gottesman-Kitaev-Preskill states, among other states.Comment: 30 pages, 13 figure

EEG correlates of social interaction at distance

This study investigated EEG correlates of social interaction at distance between twenty-five pairs of participants who were not connected by any traditional channels of communication. Each session involved the application of 128 stimulations separated by intervals of random duration ranging from 4 to 6 seconds. One of the pair received a one-second stimulation from a light signal produced by an arrangement of red LEDs, and a simultaneous 500 Hz sinusoidal audio signal of the same length. The other member of the pair sat in an isolated sound-proof room, such that any sensory interaction between the pair was impossible. An analysis of the Event-Related Potentials associated with sensory stimulation using traditional averaging methods showed a distinct peak at approximately 300 ms, but only in the EEG activity of subjects who were directly stimulated. However, when a new algorithm was applied to the EEG activity based on the correlation between signals from all active electrodes, a weak but robust response was also detected in the EEG activity of the passive member of the pair, particularly within 9 – 10 Hz in the Alpha range. Using the Bootstrap method and the Monte Carlo emulation, this signal was found to be statistically significant

Gaussian conversion protocol for heralded generation of qunaught states

In the field of fault-tolerant quantum computing, continuous-variable systems can be utilized to protect quantum information from noise through the use of bosonic codes. These codes map qubit-type quantum information onto the larger bosonic Hilbert space, and can be divided into two main categories: translational-symmetric codes, such as Gottesman-Kitaev-Preskill (GKP) codes, and rotational-symmetric codes, including cat and binomial codes. The relationship between these families of codes has not yet been fully understood. We present an iterative protocol for converting between two instances of these codes GKP qunaught states and four-foldsymmetric binomial states corresponding to a zero-logical encoded qubit - using only Gaussian operations. This conversion demonstrates the potential for universality of binomial states for all-Gaussian quantum computation and provides a new method for the heraladed preparation of GKP states. Through numerical simulation, we obtain GKP qunaught states with a fidelity of over 98% and a probability of approximately 3.14%, after only two steps of our iterative protocol, though higher fidelities can be achieved with additional iterations at the cost of lower success probabilities.Comment: 10 page

Universal Gate Set for Continuous-Variable Quantum Computation with Microwave Circuits

We provide an explicit construction of a universal gate set for continuous-variable quantum computation with microwave circuits. Such a universal set has been first proposed in quantum-optical setups, but its experimental implementation has remained elusive in that domain due to the difficulties in engineering strong nonlinearities. Here, we show that a realistic microwave architecture allows to overcome this difficulty. As an application, we show that this architecture allows to generate a cubic phase state with an experimentally feasible procedure. This work highlights a practical advantage of microwave circuits with respect to optical systems for the purpose of engineering non-Gaussian states, and opens the quest for continuous-variable algorithms based on a few repetitions of elementary gates from the continuous-variable universal set.Comment: 6+6 pages, 2 figure

How Many Bodies Are There? Unexpected Discoveries About the Subtle Body and Psychic Body

1. Patrizio E. Tressoldi[1][1][⇑][2] 2. Luciano Pederzoli[2][3] 3. Patrizio Caini[2][3] 4. Alessandro Ferrini[2][3] 5. Simone Melloni[2][3] 6. Elena Prati[2][3] 7. Diana Richeldi[2][3] 8. Florentina Richeldi[2][3] 9. Alice Trabucco[2][3] 1. 1Universita di Padova, Italy 2. 2EvanLab, Firenze, Italy 1. Patrizio E. Tressoldi, Universita di Padova, via Venezia 8, Padova 35131, Italy. Email: patrizio.tressoldi{at}unipd.it The possibility to induce real out-of-body experiences (OBEs) using hypnotic inductions, with the opportunity to interview participants during their experience, permits to investigate in depth the characteristics of different aspects of this particular state of consciousness from a first-person point of view. In this article, six selected participants report the description of another "body" we named "subtle body," identified as an intermediate entity between the physical body (Pb) and their "Self" or "I-identity" that was named "psychic body," and their relationships and characteristics. The "subtle body" was described as a sort of white silvered cloud surrounding the Pb, with a particular enlargement of its hands and feet that could move quickly like flying from one place to another even if less easily than the "psychic body," and a vague sense of attrition was perceived when passing through walls. Similar to the "psychic body," the "subtle" one too could move forward and backward in time even if they did not seem perceiving the sense of time. The "subtle body" was referred to be connected with the physical one by a sort of white brilliant link sometimes described like a silvered string more or less visible, whereas no visible links were identified between the "subtle body" and the "psychic" one. These reports were compared with similar descriptions deriving from the Vedanta philosophy and Theosophical tradition. [1]: #aff-1 [2]: #corresp-1 [3]: #aff-

Brain-to-Brain (mind-to-mind) interaction at distance: a confirmatory study

This study reports the results of a confirmatory experiment testing the hypothesis that it is possible to detect coincidences of a sequence of events (silence-signal) of different length, by analyzing the EEG activity of two human partners spatially separated when one member of the pair receives the stimulation and the second one is connected only mentally with the first. Seven selected participants with a long friendship and a capacity to maintain focused mental concentration, were divided into two groups located in two different laboratories approximately 190 km apart. Each participant acted both as a “stimulated” and as a “mentally connected” member of the pair for a total of twenty sessions overall. The offline analysis of EEG activity using a special classification algorithm based on a support vector machine, detected the coincidences in the sequence of events of the stimulation protocol between the EEG activity of the “stimulated” and the “mentally connected” pairs. Furthermore the correlation of the power spectra of the five EEG frequency bands between each of the twenty pairs of data was analyzed using a bootstrap procedure. The overall percentage of coincidences out of 88 events was 78.4% and the statistically significant average correlations between the EEG alpha and gamma bands among the pairs of participants, confirmed the results observed in a pilot study. The examination of potential internal, external and statistical artifacts which might have caused these results, ruled out external and internal artifacts. However, the examination of potential statistical artifacts revealed a good level of coincidences in only four pairs using a new procedure to detect the sequences of silence and signal between the EEG activity of the pairs of participants, giving a mild support to the hypothesis that two brains and hence two minds can be connected at distance