Quantum strategy offers game-winning advantages, even without entanglement

By Lisa Zyga PhysOrg.com

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Experimental and theoretical results both show that quantum gain - measured as the difference between the winning chances for classical and quantum players - is highest under maximum entanglement. Quantum gain remains even when entanglement disappears, and approaches zero along with the discord. Image credit: Zu, et al. ©2012 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft

(PhysOrg.com) -- Quantum correlations have well-known advantages in areas such as communication, computing, and cryptography, and recently physicists have discovered that they may help players competing in zero-sum games, as well. In a new study, researchers have found that a game player who uses an appropriate quantum strategy can greatly increase their chances of winning compared with using a classical strategy.

The researchers, Chong Zu from Tsingua University in Beijing, China, and coauthors, have published their study on how quantum mechanics can help game players in a recent issue of the New Journal of Physics.

In their study, the researchers focused on a two-player game called matching pennies. In the classical version of this game, each player puts down one penny as either heads or tails. If both pennies match, then Player 1 wins and takes both pennies. If one penny shows heads and the other shows tails, then Player 2 wins and takes both pennies. Since one player’s gain is always the other player’s loss, the game is a zero-sum game.

In the classical version of the game, neither player has any incentive to choose one side of the coin over the other, so players choose heads or tails with equal probability. The random nature of the players’ strategies results in a “mixed strategy Nash equilibrium,” a situation in which each player has only a 50% chance of winning, no matter what strategy they use.

But here, Zu and coauthors have found that a player who has the option of using a quantum strategy can increase his or her chances of winning from 50% to 94%. This quantum version of the game uses entangled photons as qubits instead of pennies. And instead of choosing between heads and tails, players use a polarizer and single-photon detector to implement their strategies. While the classical player can still choose only one of two states, the quantum player has more choices due to her ability to rotate a polarizer 360° before the single-photon detector. The researchers calculated that the quantum player can maximize his or her chances of winning by rotating the polarizer at a 45° angle.

“Each player can apply any operation to their qubit (or coin), and then measure it in computational basis,” Zu explained to PhysOrg.com. “For a classical player, the operation he can do is to flip the bit or just leave it unchanged. However, if a player has quantum power, he can apply arbitrary single-bit operations to his qubit. But the measurement part is the same for the quantum and classical players.”

The researchers found that the quantum advantage depends heavily on how correlated the original photons are, with a maximally entangled state providing the largest gain. The researchers were surprised to find that the quantum advantage doesn’t decrease to zero when entanglement disappears completely, since a different kind of quantum correlation – quantum discord – also provides an advantage. This finding may even be the most interesting part of the study.

“There is no wonder that quantum mechanics will lead to advantages in game theory, but the interesting part of our work is that we find out the quantum gain does not decrease to zero when entanglement disappears,” Zu said. “Instead, it links with another kind of quantum correlation described by discord for the qubit case, and the connection is demonstrated both theoretically and experimentally.”

He added that this finding could potentially be useful for making real-world strategies.

“Our work may help people to understand how quantum mechanics works in game theory (in some cases, entanglement is not necessary for a quantum player to achieve a positive gain),” he said. “It may also give a good example of people making strategies in a future quantum network.”

More information: C. Zu, et al. “Experimental demonstration of quantum gain in a zero-sum game.” New Journal of Physics, 14 (2012) 033002. DOI: 10.1088/1367-2630/14/3/033002

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NFCorp Boss Charged With CBT in 'Cowgate' scandal!

Day in court: Datuk Seri Dr Mohamad Salleh Ismail (above) leaving the courthouse after being charged. Also present were his wife Datuk Seri Shahrizat Abdul Jalil and their son Wan Shahinur Izmir Salleh (below).

By MAIZATUL NAZLINA and TERENCE TOH newsdesk@thestar.com.my

KUALA LUMPUR: The executive chairman of the National Feedlot Corporation Sdn Bhd has claimed trial at the Sessions Court here to two counts of committing breach of trust and two counts of violating the Companies Act 1965 involving RM49.7mil.

Datuk Seri Dr Mohamad Salleh Ismail, 64, arrived in court at 2.15pm accompanied by his wife Datuk Seri Shahrizat Abdul Jalil, their eldest son Wan Shahinur Izmir and other family members.

The charges were read to Dr Mohamad Salleh at 2.27pm before judge S.M. Komathy Suppiah in a packed courtroom.

The proceedings yesterday marked a new chapter in the NFCorp controversy which arose after the Auditor-General's 2010 Report highlighted the failure of the National Feedlot Centre to achieve its target, and which grew with revelations that the company had used the government-funded soft loan for purposes not related to cattle breeding.



Dr Mohamad Salleh was charged with dishonestly misusing funds amounting to RM9,758,140 through four cheques to partly finance the purchase of two units of One Menerung Condominium in Block B here for the National Meat and Livestock Corporation Sdn Bhd, which he owns with one of his sons.



According to the charge, he committed the offence in his capacity as an NFCorp director entrusted with control over the company's assets.

He is said to have committed the offence at CIMB Islamic Bank Bhd in Jalan Burhanuddin Helmi, Taman Tun Dr Ismail, here between Dec 1 and 4, 2009.

Dr Mohamad Salleh was charged under Section 409 of the Penal Code which carries a jail term of up to 20 years, a fine and whipping.

He is also accused under Section 132(2)(a) of the Companies Act 1965 of committing the offence without approval from an annual general meeting of NFCorp to gain profit directly.

He is also accused of transferring NFCorp's funds of RM40mil through a cheque into the National Meat and Livestock Corporation's account at the same bank from May 6 to Nov 16, 2009.

For this, he faces charges of criminal breach of trust and violating the Companies Act.

Deputy Public Prosecutors Dzulkifli Ahmad, Awang Armadajaya Awang Mahmud and Azimul Azami prosecuted while the defence was led by Badrul Munir Bukhari.

Pleading for a lower bail, counsel Badrul Munir said Dr Mohamad Salleh had given his full cooperation to the police and prosecution, and his client was in court to clear his name. He applied to release the accused on a RM50,000 personal bond for each charge.

Dzulkifli said the prosecution had no objection to the application as they did not see why Dr Mohamad Salleh would flee the country. He, however, said the accused should surrender all his travel documents to the court.

Dzulkifli applied to the court under Section 165 of the Criminal Procedure Code for a single trial for all the charges.

Judge Komathy agreed to a single trial and set bail of RM500,000 with one surety for all four charges.
She also ordered Mohamad Salleh to surrender his passport pending mention of his case on April 13.

Wan Shahinur Izmir paid the bail.

Shahrizat was impassive in court and declined to speak to reporters after the proceedings.

Malaysian minister to step down in midst of 'Cowgate' scandal
By THE ASSOCIATED PRESS

U.S. Secretary of State Hillary Rodham Clinton, right, is greeted by Malaysian Minister of Women, Family, and Community Development Shahrizat Abdul Jalil before a town hall event at the International Institute of Islamic Thought and Civilization on Tuesday, Nov. 2, 2010, in Kuala Lumpur, Malaysia. (EVAN VUCCI / AP)

KUALA LUMPUR, Malaysia — A Malaysian minister said Sunday she will step down amid accusations that her family misused a 250 million ringgit ($83 million) government loan meant for a cattle project to purchase condominiums, vacations and a Mercedes. 

The scandal, dubbed "Cowgate,'' has greatly embarrassed Prime Minister Najib Razak ahead of general elections widely expected to be called by June. 

After months of resisting calls from critics to step down, Shahrizat Abdul Jalil said she will resign as minister of women, family and community on April 8 once her term as senator ends. 

Shahrizat said her decision had nothing to do with the cattle project run by her husband and three children but that she is stepping down as a "responsible member of the government.'' She will, however, stay on as chief of the women's wing of the ruling Malay party. 

The scandal emerged last year after the auditor-general's annual report said the National Feedlot Center run by Shahrizat's family had not met its goal of making the country 40 per cent self-sufficient in beef production by 2010. 

Since then, opposition parties have accused the company of using a government loan allocated for cattle rearing to purchase property including luxury condominiums in Malaysia and Singapore and other personal items. Shahrizat's family has denied any wrongdoing, saying the company was allowed to use the loan at its discretion and that the properties would earn it rental income. 

Police have recommended that the company's directors be charged with criminal breach of trust but the attorney-general has asked police to conduct further investigations. 

Najib said Shahrizat's resignation was a sacrifice in the interest of the government and party. 

"Although there is no proof so far that she had committed any offence in terms of law, because the (project) has drawn controversy and dispute, she was willing to withdraw from the government,'' the national Bernama news agency quoted him as saying. 

Analysts said Shahrizat's resignation wasn't surprising as Najib isn't likely to renew her senatorship. 

"Cowgate is a big blow to Najib as it shows he is slow to act on allegations of high-level corruption,'' said James Chin, a political science lecturer at Monash University in Malaysia. 

Najib's National Front coalition suffered its worst performance in 2008 polls, losing more than a third of Parliament's seats to a resurgent opposition amid widespread discontent over the government's handling of problems such as corruption and racial discrimination. 

While the ruling coalition isn't expected to lose power in upcoming polls, scandals such as Cowgate make it tougher for Najib to consolidate his power. General elections are not due until 2013 but are widely expected in the next few months.

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Fukushima nuclear meltdown - one year later

GLOBAL TRENDS By MARTIN KHOR
 
As the world marks the first anniversary of Japan’s triple tragedy, lessons are still being drawn from the Fukushima nuclear accident and the dangers of nuclear power plants.

 IT’S been a full year since Japan’s triple disaster of earthquake, tsunami and nuclear meltdown, and the reverberations are still being felt.

The tsunami on March 11, 2011, caused around 19,000 deaths (16,000 known dead, 3,000 missing) and 320,000 were made homeless.

The nuclear disaster alone created 100,000 nuclear evacuees.

The lesson, only partially learnt in Japan itself and hardly learnt in other countries, is that natural disasters can come in many unexpected forms and governments must put aside considerable resources and facilities to prepare for and manage them.



The lesson usually becomes obvious when a disaster occurs.

After that, a pledge is made to be better prepared and much of that is not implemented until the next disaster and the cycle begins again.

While the tsunami caused the most immediate damage, it was the nuclear incidents at the Fukushima power plant that were the most shocking and may have the most long-term repercussions.

The nuclear disaster blew away a lot of myths.We now know, again, that nuclear power plants are not safe.

The claim by Tepco – the Japanese company operating the Fukushima plant – that the reactors were fail-safe and could withstand earthquakes, was proven to be wrong.

The ability of the regulatory autho­rities to monitor and check for risks and ensure safety was near absent.
An independent commission, which was set up by the Rebuild Japan Initiative Foundation to investigate the nuclear incident, shows how close Japan came to a catastrophe.

Its chairman Yoichi Funabashi, in an article in last Saturday’s Financial Times, said that Japan was on the edge of an “existential crisis”.

As the tsunami knocked out the Fukushima plant’s cooling systems, the Tepco president indicated his company’s intention to abandon the plant and evacuate its workers.

Japanese Prime Minister Naoto Kan personally intervened, ordering the company not to abandon ship and form a “death squad” to continue the battle and inject water into the reactor vessels.

A worst case scenario, prepared for the prime minister by the Japan Atomic Energy Commission, envisioned a hydrogen explosion, a succession of meltdowns and such extensive radiation that the whole of Tokyo would have to be evacuated.

Funabashi said: “The truth is that the imagined ‘worst-case scenario’ was closer than anyone would wish to admit; but for the direction of the wind (towards the Pacific, not inland, in the four days after the earthquake); but for the manner in which the gate separating the reactor-well and the spent-fuel pool in Unit 4 broke (presumably facilitating the transfusion of water into the pool). Luck was undeniably on our side.”

Funabashi’s commission found that the nuclear industry had become ensnared in its twisted myth of “absolute safety”, propagated by interest groups seeking to gain broad acceptance of nuclear power.

He also found that “Japan’s nuclear safety regulatory regime was phoney. Regulators pretended to regulate; utilities pretended to be regulated. In reality, the latter were far more powerful in expertise and clout”. He offers two lessons to be learnt.

First, is the need to overcome the myth of “absolute safety”, shatter the taboo that surrounds the concept of risks in the nuclear energy business and the need to prepare for the unthinkable and unanticipated.

Second, is the need for an independent regulatory body.

A major fallout from the Fuku­shima accident is the blow it has dealt to the nuclear industry.

It highlighted the danger a country faces when something goes wrong.

Of its 52 nuclear plants, Japan has now shut down 50 plants. The remaining two may also be shut down next month.

Although the government may try to reopen some of them, the public revulsion against nuclear plants could mean that their days are numbered.

There has also been a global backlash, with Germany, Italy, Belgium and Switzerland declaring that they will phase out their nuclear plants.

The situation in Asia, however, is mixed. China has suspended the building of new nuclear plants pending changes in safety standards.
India, Vietnam and Korea are going ahead with their nuclear power programmes.

“If more nuclear power plants are built in developing countries with little experience of operating a reactor, or bordering a region where terrorism is a concern, or without sufficient financial resources to import state of the art technology, then the chance of a major nuclear accident hitting the developing world will loom large in the coming decades,” said Kevin Tu, senior associate at the Carnegie Endowment for International Peace.

Meanwhile The Economist magazine, in its latest cover story, “Nuclear Energy: The dream that failed” is pessimistic about the future of the nuclear industry.

Nuclear plants are costly to build and operate. British studies put the overnight cost of new power plants at US$2,233 (RM6,720) for every kilowatt of capacity in 2004 and US$3,000 (RM9,028)/kw in 2008, according to The Economist.

Capacity fired by gas turbines cost less than one-fifth of that. The cost of renewable energy (wind and solar, in particular) is, however, getting cheaper every year.

Perhaps, the most intractable problem is nuclear waste. As The Economist noted, building a nuclear plant that can last 100 years is one thing, but creating waste that will be dangerous for 100 times as long is another.

So far, countries have failed to create a long-term repository for nuclear waste.

As the public has become intensely more aware of the dangers of radiation, the resistance to locating nuclear plants in their neighbourhood has grown fiercer.

No doubt the Fukushima meltdowns and its aftermath have contributed to increased awareness and to the bad name that nuclear power has acquired.

P/S:  We sympathize with Japan's sufferings from earthquake, tsunami caused by nature that resulted in Fukushima nuclear meltdown a year ago.

How Japan feels when we remember the victims of its Nanjing Massacre committed and occupied by Japanese troops on Dec 13, 1937, China's former capital city suffered a six-week massacre in which more than  300,000 Chinese were Killed, 20,000 Women Raped ... ?


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